To find the missing dimension of the tabletop, the height, you will use the formula for finding the area of a trapezoid and solve for the missing height.
A = 1/2 h (b1 + b2)
6550 = 1/2 h (115 + 85)
6550 = 1/2 h (200)
6550 = 100h
100 100
655 = h
The height is 655 cm.