STEP-BY-STEP SOLUTION:
First of all, let's establish the angle sum of the shape as displayed below;
Angle sum of a polygon = 180° × no. of triangles in polygon = 180° × 4 = 720°
Now, let's simply subtract the values of all the other angles from the angle sum in order to find the value of angle ( A ) as displayed below:
A + 120 + 110 + 230 + 50 + 100 = 720
A = 720 - 120 - 110 - 230 - 50 - 100
A = 110°
Therefore, the answer is:
Option A - 110°
