Area of Trapezoids

1
Area of Trapezoids
Trapezoids are quadrilaterals with exactly one
set of parallel lines. It is not a parallelogram.
base a
height
base a
base b
height
base b
The lines that are parallel on a trapezoid are
also the two bases.
The height is perpendicular to the base but it
happens to also be the distance between the two
bases.
2
Area of a trapezoid ½ h (base a base b)
A ½ h ( a b ) ½ ( 5 ) ( 4 8 ) ½ (
5 ) ( 12 ) A 30 in²
a 4 in
h 5 in
b 8 in
A ½ h ( a b ) ½ ( 10 ) ( 9 15 ) ½ (
10 ) ( 24 ) A 120 cm²
b 15 cm
a 9 cm
h 10 cm
3
a 7 in
Ex. 1
Use the formula A ½ h ( a b )
h 6 in
b 4 in
1.5 ft
Ex. 3
Ex. 2
1. A33 in²
b12 m
10 ft
a5 m
2. A17 m²
h2 m
3. A 20ft²
8 ft
3.5 ft