The measure of the missing angle(a) in the isosceles triangle(two sides and angle equal) is 70 degrees.
What is an Isosceles triangle?
An Isosceles triangle is a triangle that has two of it sides equal to each other and two of it angles equal to each other.
The base angle of an isosceles triangle are equal. Therefore, let's find angle a in the triangle.
55 + 55 + a = 180
Recall the sum of angle in a triangle is 180 degrees.
110 + a = 180
subtract 110 from both sides
110 - 110 + a = 180 - 110
a = 70 degrees
learn more on Isosceles triangle here: https://brainly.com/question/4264350
