http://www.ck12.org Chapter 10. Perimeter and Area
A=h(b 1 +b 2 )Because the area of this parallelogram is made up of two congruent trapezoids, thearea of one trapezoidwould be
A=^12 h(b 1 +b 2 ). The formula for the area of a trapezoid could also be written asthe average of the bases time the
height.
Example A
Find the area of the trapezoid below.
A=
1
2
( 11 )( 14 + 8 )
A=
1
2
( 11 )( 22 )
A= 121 units^2Example B
Find the area of the trapezoid below.
A=
1
2
( 9 )( 15 + 23 )
A=
1
2
( 9 )( 38 )
A= 171 units^2