Question

in figure ab||cd and a transversal l cuts ab and cd at a and c respectively bisectors of angle a and angle c intersect at each other at p prove that angle apc = 90 degree

Answer 1

Angle a + angle c = 180° 1/2(Angle a + angle c = 180°) 1/2 of angle a + 1/2 of angle c = 90° - ( i) Now in triangle apc, 1/2 of angle a + 1/2 of angle c + angle apc = 180° From (i) equantion, Angle apc = 90°