The trapezoid in the figure has equal nonparallel sides. the upper base is 6, the lower base is 16, and the diagonal is 12. what is the altitude of the trapezoid?
a. 5.7
b. 4.8
c.7.9
d. 8.4

Answer=B 4.8

We have a right triangle in the drawing so for the altitude we can use the pythagorean theorem. It's as follows...

a²+b²=c²    (where a and b are the side lengths and c is the hypothenuse)

Lets input in the data that we have.

11²+b²=12²
simplify
121+b²=144
subtract 121 from both sides
b²=23

To solve for the missing side/altitude we just need to find the square root of 23

b=√23
b=4.79 or 4.8

Answer=B