Step-by-step explanation:
Since we know that it is an isosceles triangle those to base angles are equal which mean 70°,70° now
we are left to find the upper angle let name it y
so to find
it will be
70°+70°+y=180°(angles in a triangle)
y+140=180
simplify
you will get y to be 40°
which means y=40°
now to find x
y+x=180°(angles on a straight line)
x+40°=180°
x=140°
