REC

TA

NG

LE

P= 2L + 2WR

EC

TA

NG

LE

TRIANGLE

P = a + b + c

TRIANGLEA = ½(8*8)A = 32

P = 8 + 4 + 8 =20

PARALLELOGRAM

P=2(w+h)

Find the area of a parallelogram with a base of 12 centimeters and a height of 5 centimeters.

= (12 cm) · (5 cm)

= 60 cm

PerimeterThe perimeter of a parallelogram is the sum of the lengths of all its sides. Example: What is the perimeter of a parallelogram having side-lengths of 3.4 cm and 8.2 cm? Since a parallelogram has 4 sides, and the opposite sides of a parallelogram have the same length, a parallelogram has 2 sides of length 3.4 cm, and 2 sides of length 8.2 cm. The sum of the lengths of all the sides of the parallelogram is 3.4 + 3.4 + 8.2 + 8.2 = 23.2 cm

CIRCLE

  = 3.14 · (3 in) · (3 in)

  = 3.14 · (9 in2)

  = 28.26 in2

SquareArea square = s2

Area square = 42

Area square = 16

CircleArea circle = pi × r2

Notice that the radius of the circle is 4/2 = 2Area circle = 3.14 × 22

Area circle = 3.14 × 4

Area circle = 12.56

Since you only have half a circle, you have to multiply the result by 1/2

1/2 × 12.56 = 6.28

Area of this shape = 16 + 6.28 = 22.28

To find the area of irregular shapes, the first thing to do is to divide the irregular shape into regular shapes that you can recognize such as triangles, rectangles, circles, squares and so forth...

Then, find the area of these individual shapes and add them up!

De’Quan

PERIOD 6

Ms. Togans

Holloway