it ia an isoceles triangle , it has two equal sides and two equal angles
the sum of angles in a triangle is = 180
let the angles be x, y and z
x+ y+ z= 180
x= y ( isoceles triangle )
z= 40 ( given )
so we can write
2x + z= 180
2x + 40 = 180
2x = 140 x= 70
