The height of trapezoid VWXZ is 8 StartRoot 3 EndRoot units. The upper base,VW, measures 10 units. Use the 30°-60°-90° triangle theorem to find the length of YX. Trapezoid V W X Z is shown. A line is drawn from point W to point Y on side Z X, forming a right angle. Angles W V Z and V Z Y are right angles. The length of V W is 10 and the length of W Y is 8 StartRoot 3 EndRoot. Angle YW X is 30 degrees, and angle W X Y is 60 degrees. Once you you know the length of YX, find the length of the lower base, ZX. 14 units 10 + 4 StartRoot 3 EndRoot units 18 units 10 + 8 StartRoot 3 EndRoot units