Question

A collage in the shape of a regular heptagon is mounted on a rectangular frame as shown below.



Which is closest to the value of x?

15

40

50

25

Answer 1

Sum of Interior Angles in a polygon = (n-2)*180

5*180=900

So one interior angle is 900/7=128.571429

Now we do 180-128.571429 so we get the other angle in the triangle.

=51.428571

And good old 180-90-51.428571=38.571429

x=38.571429

your answer is 40