HELP I DONT UNDERSTAND THIS

Step-by-step explanation:

First, let's look at the largest triangle (two smaller triangles are combined) to solve for . Since the sum of the angles in a triangle adds up to , we can write the equation:

Looking at the smaller triangle on the left, (exterior angle) is the sum of the two opposite interior angles of the triangle on the left:

Since is the exterior angle of the triangle on the right, it is equivalent to the sum of the opposite interior angles of that triangle:

Hope this helps :)

1/800 is the right answer