Since m∠8 = 92 and m∠12 = 37
m∠9 = ?
5) Angle ∠9 is collateral to angle ∠8. Therefore it is a supplementary angle.
m∠9= 180º-m∠8
m∠9=180-92
m∠9=88º
6) m∠11 =?
Angle ∠11 is supplementary to angle 12, for ∠11+∠12= 180º
∠11+∠12= 180º
∠11+37= 180º
∠11=143º
∠
≅
⇒
