Respuesta :
Answer:
70
Step-by-step explanation:
the red lines mean the two sides are equal
so its an isosceles triangle meaning the two angles other than the 40° one are equal
the inner angles of a triangle must add up to 180
so 180-40 = 2x
140 = 2x
x = 140/2 = 70
Answer:
x=70
Step-by-step explanation:
let unknown angle be a
then,a=x(base angle of an isosceles triangle)
a+x+40=180
x+x=180-40(a=x)
2x=140
x=70