Answer:
72
Explanation:
We know that , the sum of interior angles of any shape can be measured using the formula: (n-2)× 180; where, n is the number of sides in the shape.
Here, the figure is a triangle. Therefore,
n= 3
(3-2)* 180=180°
Hence, the sum of all angles in this figure is 180.
That is, 77+31+x= 180°
108+x=180°
x= 180-108= 72°
Therefore, x= 72°