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In the figure below, a circle of radius 4 inches is inscribed in a trapezoid ABCD whose longer base is 12 inches. Find the area of the trapezoid. Give exact answer including units.

In the figure below, a circle of radius 4 inches is inscribed in a trapezoid ABCD whose longer base is 12 inches. Find the area of the trapezoid. Give exact ans class=

Verified Answer :

area of a trapezoid = (a+b)/2 h

b = 12 ; h = (4x2)= 8 ; a = ?

I'm assuming that a = 6.  Based on the figure, the upper base is shorter compared to the diameter of the inscribed circle. It seems as though it only covers 75% of the diameter. So, 8 is the diameter. 75% of it is 6.

Area = (6inches +12 inches )/2
8 inches
A = 18 inches/2 8 inches
A = 9 inches
8 inches
A = 72 square inches. 

The area of the trapezoid is 72 square inches.