Question

from the fir angle A=
​

Answer 1

angle A = 70°

As given in figure

PQ is parallel to line ST

QR is transversal passing through PQ and ST

Angle PQR =40° Angle PRQ =70°

According to Alternate interior angle theorem

angle PQR =angle QRT=40°

Also angle PRS + angle PRQ+angle QRT =180°

Therefore ,angleA+70°+40°=180°

angle A + 110°=180°

angle A = 180°-110°

angle A =70°