Question 912739


Let ABC be the triangle

AE is drawn parallel to BC

CAF is the external angle

To prove AE bisects CAF

AE is parallel to BC and AC is the transversal

So angle CAE = ACB ( alternate angle test)

AE is parallel to BC and Bf is the transversal
so EAF = ABC ( corresponding angles test)

But ABC = ACB ( isosceles triangle)

therefore EAF = CAE