Answer:
x = 54°
Explanation:
The sum of the interior angles of a polygon is
sum = 180° (n - 2) ← n is the number of sides
Here n = 5, thus
sum = 180° × 3 = 540°
Each interior angle is therefore 540° ÷ 5 = 108°
Since the triangles are congruent then x = 108° ÷ 2 = 54°