Question 973882
30-60-90 triangles are 1, sqrt(3) and 2, where 2 is the hypotenuse.

x is the height, and it is 15, half of 30.  The base is15 sqrt(3)).

By the Pythagorean Theorem, 15^2=225, (15 sqrt(3))^2= 675, and 30^2 =900, the sum of the first two.