Những câu hỏi liên quan
PT
Xem chi tiết
TD
15 tháng 6 2022 lúc 20:29

chịu hoi =))))))

 

Bình luận (0)
TD
15 tháng 6 2022 lúc 20:29

em mới học lớp 7 hà

năm nay lên lớp 8 =)))))

Bình luận (0)
NM
14 tháng 1 2023 lúc 21:25

1)Ta có: \(S_{ABC}=\dfrac{1}{2}AB.AC.\sin A\)

\(\Leftrightarrow8=\dfrac{1}{2}\times4\times5\times sinA\)

\(\Leftrightarrow\sin A=0,8\)

Lại có: \(\left(\sin A\right)^2+\left(\cos A\right)^2=1\Leftrightarrow\cos A=0,6.\)

Áp dụng định lí hàm số cosin:

\(BC^2=AB^2+AC^2-2AB\times AC\times\cos A\)

\(\Leftrightarrow BC^2=4^2+5^2-2\times4\times5\times0,6=17\)

\(\Leftrightarrow BC=\sqrt{17}.\)

2) Trong \(\Delta ABC\) có: \(g\text{ó}cA+g\text{óc}B+g\text{óc}C=180^o\)

=> BAC=75o.

Áp dụng định lí hàm số sin:

\(\dfrac{AB}{\sin C}=\dfrac{BC}{\sin A}\Leftrightarrow\dfrac{3}{\sin45^o}=\dfrac{BC}{\sin75^o}\)

\(\Leftrightarrow BC=\dfrac{3+3\sqrt{3}}{2}\).

 

 

Bình luận (0)
HD
Xem chi tiết
NA
Xem chi tiết
NA
15 tháng 3 2021 lúc 18:07

Sao tôi viết câu hỏi nhưng chỉ hiển thị có 1 dòng

Bình luận (2)
H24
15 tháng 3 2021 lúc 18:09

Xem ảnh nguồn

Bình luận (0)
NA
15 tháng 3 2021 lúc 18:14

Câu hỏi đây mọi người giải giúo mình nhé. Xin cảm ơn

undefined

Bình luận (0)
NT
Xem chi tiết
DL
22 tháng 12 2021 lúc 8:49

thiếu kìa

Bình luận (0)
DN
Xem chi tiết
H24
Xem chi tiết
H24
Xem chi tiết
TD
15 tháng 6 2022 lúc 20:31

https://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.htmlhttps://olm.vn/hoi-dap/detail/239868952049.html

Bình luận (0)
BT
Xem chi tiết
TD
15 tháng 6 2022 lúc 20:34

câu 1 E + F = 90 độ

câu 2 góc AMB và góc AMC

câu 3 AC = MP

 

Bình luận (0)
ST
Xem chi tiết
H24
2 tháng 7 2019 lúc 8:07

Gọi ( O;R ) , ( I ;r ) lần lượt là các đường tròn ngoại tiếp tam giác ABC, DEF 

Tam giác ABC ~ Tam giác DEF ( vì \(\widehat{ABC}=\widehat{DEF};\widehat{BAC}=\widehat{EDF}\)\(\Rightarrow\widehat{ABC}=\widehat{DEF}\)

\(\widehat{ACB},\widehat{DEF}\)nhọn nên \(\widehat{ACB}=\frac{1}{2}\widehat{AOB};\widehat{DEF}=\frac{1}{2}\widehat{DIE}\)( hệ quả góc nội tiếp )

\(\Rightarrow\widehat{AOB}=\widehat{DIE}\)

     \(OA=OB\left(=R\right)\Rightarrow\Delta OAB\)cân tại O

    \(ID=IE\left(=r\right)\Rightarrow\Delta IDE\)cân tại I

Do đó Tam giác OAB ~ Tam giác IDE \(\Rightarrow\frac{OA}{ID}=\frac{AB}{DE}\Rightarrow\frac{R}{r}=\frac{3DE}{DE}\)

                                                           \(\Rightarrow R=3r\) ( đpcm)

Bình luận (0)
DL
5 tháng 7 2019 lúc 7:24

Gọi ( O; R ), ( I; R ) lần lượt là các đường tròn ngoại tiếp tam giác ABC, DEF

Tam giác ABC ~ Tam giác DEF ( vì \(\widehat{ABC}=\widehat{DEF;}\widehat{BAC}=\widehat{EDF}\)  ) \(\Rightarrow\widehat{ABC}=\widehat{DEF}\)

\(\widehat{ABC}=\widehat{DEF}\)nhọn nên \(\widehat{ACB}=\frac{1}{2}\widehat{AOB};\widehat{DEF}=\frac{1}{2}\widehat{DIE}\)(hệ quả góc nội tiếp )

\(\Rightarrow\widehat{AOB}=\widehat{DIE}\)

\(OA=OA\left(=R\right)\Rightarrow\Delta OAB\)cân tại O

Do đó Tam giác OAB ~ Tam giác IDE\(\Rightarrow\frac{OA}{ID}=\frac{AB}{DE}\Rightarrow\frac{R}{r}=\frac{3DE}{DE}\)

                                                       \(\Rightarrow R=3r\left(đpcm\right)\)

  Rất vui vì giúp đc bạn <3

Bình luận (0)