Find the area of an isosceles trapezoid if its base is 5 cm and 16 cm and the side is 13.

Let’s mentally lower the height in this trapezoid. It forms a right-angled triangle, in which the side of the trapezium will be the hypotenuse, and the height of the leg.

Determine how many centimeters the second leg in this right-angled triangle will be equal to when we know that the bases of the trapezoid are 5 and 16 centimeters, respectively:

(16 – 5): 2 = 11/2 = 5.5.

Let’s determine how many centimeters the height will be:

√ (13 ^ 2 – 5.5 ^ 2) = √138.75.

Determine the area of the trapezoid:

(16 + 5): 2 * √138.75 = 10.5√138.75.

Answer: 10.5√138.75 cm2.