# Thread: ABC the Triangle (urgent)

1. ## ABC the Triangle (urgent)

let ABC be a triangle with AB=AC. D is a point on AC such that BC=BD. E is a point on AB such that BE=ED=AD. Find the angle size of EAD

please someone help, and also if u can show some working out that wouldbe great

thnx a million
justanotherperson

2. ## Isosceles triangles

Hello justanotherperson
Originally Posted by justanotherperson
let ABC be a triangle with AB=AC. D is a point on AC such that BC=BD. E is a point on AB such that BE=ED=AD. Find the angle size of EAD

please someone help, and also if u can show some working out that wouldbe great

thnx a million
justanotherperson
Look at the diagram I've attached, which shows all the equal angles in the various isosceles triangles.

In $\displaystyle \triangle ABC: 2x+z = 180$

In $\displaystyle \triangle BDC: 2x + (x-y) = 180$

In $\displaystyle \triangle EBD: 2y + (180 - z) = 180$

Solve these equations to find the value of $\displaystyle z\,\, ( = \angle EAD)$

I make it: $\displaystyle x = 67\tfrac12^o, y = 22\tfrac12^o, z = 45^o$.

Can you see how to get these answers?

Grandad