In the given triangle, two sides are equal, so the triangle is an isosceles triangle.
And in an isosceles triangle, base angles are equal.
And it is given that one angle is 56 degree, so the other base angle is 56 degree too .
And the sum of measurements of angles of a triangle is 180 degree.
So we will get
![image](https://img.qammunity.org/2019/formulas/mathematics/middle-school/hppd0mqtycyzntixh2gh0e36scze996x0g.png)
Correct option is the third option .