Respuesta :

Answer:

170 ft²

Step-by-step explanation:

First let's calculate the height of this trapezoid.  Call it 'h.'  Look at the triangle on the right; the base is equal to (22 ft - 12 ft), or (10 ft).  Using the tangent function, we can find h:

                    h

tan 45° = ---------- = 1  and so we know that h = 10 ft

                  10 ft

The formula for the area of a trapezoid is

A = (average length)*(width)

Here we have:

A = [ (12 ft + 22 ft) / 2 ] * 10 ft, or

A  =           (17 ft)*(10 ft) = 170 ft²