Definition: Rectangle
A rectangle is a quadrilateral with four
right angles.
Area: Rectangle
W
L
L = Length
W = Width
Area = L x W sq units
Example: Rectangle
3 ft
9 ft
Area = 9 ft x 3 ft
Area = 27 sq ft
Definition: Square
A square is a quadrilateral with four
congruent sides and four right angles.
Area: Square
S
S = Length of each side
Area = S x S sq units
Example: Square
8 cm
Area = 8 cm x 8 cm
Area = 64 sq cm
Definition: Triangle
A triangle is a polygon with three sides.
Area: Triangle
H
H
B
B = Base
H = Height
Area = ½ B x H sq units
B
Example: Triangle
6 ft
12 ft
Area = ½ x 12 ft x 6 ft
Area = 36 sq ft
Definition: Trapezoid
A trapezoid is a quadrilateral with only
two sides parallel.
Area: Trapezoid
B1
H
B2
B1 = Base 1
B2 = Base 2
H = Height
Area = ½ x (B1 + B2) x H sq units
Example: Trapezoid
4m
5m
8m
Area = ½ x (4m + 8m) x 5 m
Area = 30 sq m
Definition: Circle
A circle is a set of all points in a plane that
are an equal distance from its center.
Area: Circle
r
r = radius
Area =  r
2
sq units
Example: Circle
6 in.
Area
Area
Area
Area
=
=
=
=
 r 2 sq units
3.14 x (6 in.)2
3.14 x 36 sq in.
113.04 sq in.
  3.14
Try these
problems on
your own.
Find the area of the rectangle below.
5 ft
7 ft
Area = 7 ft x 5 ft
Area = 35 sq ft
Find the area of the square below.
11 cm
Area = 11 cm x 11 cm
Area = 121 sq cm
Find the area of the figure below.
4 ft
9 ft
Area = ½ x 9 ft x 4 ft
Area = 18 sq ft
Find the area of the figure below.
7m
6m
11 m
Area = ½ x (7m + 11m) x 6 m
Area = 54 sq m
Find the area of the circle below.
8 in.
Area
Area
Area
Area
=
=
=
=
 r 2 sq units
3.14 x (8 in.)2
3.14 x 64 sq in.
200.96 sq in.
  3.14
Find the area of the rectangle below.
2.7 ft
4.5 ft
Area = 2.7 ft x 4.5 ft
Area = 12.15 sq ft
Find the area of the square below.
6.5 cm
Area = 6.5 cm x 6.5 cm
Area = 42.25 sq cm
Find the area of the figure below.
3.1 ft
7.8 ft
Area = ½ x 7.8 ft x 3.1 ft
Area = 12.09 sq ft
Find the area of the figure below.
3.6 m
6.2 m
8.4 m
Area = ½ x (3.6m + 8.4m) x 6.2 m
Area = 37.2 sq m
Find the area of the circle below.
17 in.
Area
Area
Area
Area
=
=
=
=
 r 2 sq units
3.14 x (17 in.)2
3.14 x 289 sq in.
907.46 sq in.
  3.14