What is the area of an isosceles trapezoid, if its shorter base has length of 18 cm, the length of the altitude is 9 cm, and the measure of the acute angle is 45°?a = cm2!

The formula for the area of a triangle of base b and altitude h is A = (1/2)(b)(h).

Here, b = 18 cm and h = 9 cm.  Thus, the desired area is:

        (18 cm)(9 cm)

A = = 81 cm^2

                  2

This problem gives you more info than is needed to solve it.  The area of the given triangle is 81 cm^2.