Answer:
x = 31.5
Step-by-step explanation:
The triangle on the left has 2 congruent sides and is therefore isosceles.
Thus the 2 base angles are congruent with measure
[tex]\frac{180-54}{2}[/tex] = [tex]\frac{126}{2}[/tex] = 63
The exterior angle of a triangle is equal to the sum of the 2 opposite interior angles.
The triangle on the right is also isosceles with base angles of measure x
63° is an external angle of the triangle on the right, thus
x + x = 63
2x = 63 ( divide both sides by 2 )
x = 31.5
