Since this triangle is an isosceles triangle, the missing value of x is 4. The measure of each angle is 25°.
In Mathematics and Geometry, an isosceles triangle refers to a type of triangle with two sides that are equal in length (side lengths) and two equal angles.
Since the base angles of an isosceles triangle are congruent, we have the following congruent angles from the triangle shown in the picture above. Therefore, the value of x can be determined as follows;
4x + 9 = 5x + 5
5x - 4x = 9 - 5
x = 4
For the measure of each angle, we have:
Angle = 4x + 9
Angle = 4(4) + 9
Angle = 25°.