Perimeter, Area, and Volume

3102.4.1    Using algebraic expressions solve for measures in geometric figures as well as for perimeter, area, and volume.

PERIMETER

To find the perimeter of a rectangle or square use the appropriate formula or just add up the length of the sides!

rectangle square

P= 2w + 2l P=4s

Find the perimeter of the rectangle

P = 2w+2lP = 2(5)+2(8)P = 10 + 16P = 26

8

5

8

5

Find the perimeter of the irregular figure.

Just add up all the sides

5

3

8

3

5

P=5+5+3+3+8

P=24

Formulas for FINDING AREA2

1

2

A r

A bh

A lw

A bh

Circle

Triangle

Rectangle

Parallelogram

Find the area of a circle

2A r6

2(6)A 36A

Find the area of a Triangle

7

10

1

2A= b h

A= (10)(7)1

2

A= 35

Find the area of a Rectangle

A= lwA= (25)(7)A= 175

25

7

Finding the area of a parallelogram

A= bhA=(7)(4)A= 28

4

7

FINDING VOLUME

V= lwhV=(3)(6)(4)V=72

3

6

4

Finding the volume of a cylinder

2V r h5

12

2(5) (12)V

V= 942.48

Use Algebraic Expressions

A = lwA = (x+5)(2x)A = 2x2+10x

x + 5

2x

Find the area first!

Now find the perimeter!

P = 2l + 2w

P = 2(x+5) + 2(2x)

P = 2x+10 + 4x

P = 6x+10