xét ΔMNI có
\(\widehat{M1}+\widehat{N}+\widehat{I1}=180^0\) (3 góc trong 1 tam giác)
\(\rightarrow\widehat{M1}=180-\widehat{N}-\widehat{I1}=180-60-70\\ \rightarrow\widehat{M1}=50^0\)
lại có
\(\widehat{I1}+\widehat{I2}=180^0\left(kề-bù\right)\\ \rightarrow\widehat{I2}=180-\widehat{I1}=180-70\\ \rightarrow\widehat{I2}=110^0\)
xét ΔMQI có
\(\widehat{M2}+\widehat{Q}+\widehat{I2}=180^0\) (3 góc trong 1 tam giác)
\(\rightarrow\widehat{M2}=180-\widehat{Q}-\widehat{I2}=180-30-110\\ \rightarrow\widehat{M2}=40^0\)
mà
\(\widehat{M1}+\widehat{M2}=\widehat{NMQ}\\ \rightarrow\widehat{MNQ}=40+50=90^0\)
xét ΔMNI có
ˆM1+ˆN+ˆI1=1800M1^+N^+I1^=1800 (3 góc trong 1 tam giác)
→ˆM1=180−ˆN−ˆI1=180−60−70→ˆM1=500→M1^=180−N^−I1^=180−60−70→M1^=500
lại có
ˆI1+ˆI2=1800(kề−bù)→ˆI2=180−ˆI1=180−70→ˆI2=1100I1^+I2^=1800(kề−bù)→I2^=180−I1^=180−70→I2^=1100
xét ΔMQI có
ˆM2+ˆQ+ˆI2=1800M2^+Q^+I2^=1800 (3 góc trong 1 tam giác)
→ˆM2=180−ˆQ−ˆI2=180−30−110→ˆM2=400→M2^=180−Q^−I2^=180−30−110→M2^=400
mà
ˆM1+ˆM2=ˆNMQ→ˆMNQ=40+50=900