Find the area of the picture below

In the polynomial below, what number should replace the question mark to produce a difference of squares? x2 + ? x - 36

White shapes and black shapes are used in a game. some of the shapes are circles. while the rest are squares. the ratio of the number of white shapes to the number of black shapes is 5: 11. the ratio of the number of white cicrles to the number of white squares is 3: 7. the ratio of the number of black circles to the number of black squres is 3: 8. work out what fraction of all the shapes are circles.

Write a similarity statement for the similar triangles. afgh ~ a