In triangle DEF shown below, points A, B and C are taken on DE, DF and EF respectively such that EC = AC and CF = BC. Angle D = 40∘ then what is angle ACB in degrees?
Option (c)
The angle in question is p
p+180-2x+180-2y=180∘
thus p-2(x+y)= 180∘……………..(1)
also, BDX = x+y (exterior angle= sum of 2 interior angles not adjacent to it)
x+y= 140∘………(2)
using the 2 statements, p= 100∘