Perimeter

1
Perimeter
The perimeter of a polygon is the sum of the
lengths of the sides
AB 5 (-1) 6
BC 6 (-2) 8
AB BC AC 6 8 10 24
2
Area of Squares and Rectangles
The area of a square is the length of the sides
squared. A s2
The area of a rectangle is the product of its
base and height. A bh
3
Area of Parallelograms
The area of a parallelogram is the product of any
base and its corresponding height.
A bh

• Any side can be a base

• An altitude is a segment ? to the base drawn to
  the opposite base

• The height is the length of the altitude

4
Example 2

• In parallelogram ABCD, DE and CF are altitudes.
  Find CF.

A bh 10(12) 120
A bh 13(CF) 120
CF 120/13 ? 9.2 units2
5
Area of Triangles

• The area of a triangle is half the product of any
  base and the corresponding height

6
Example 3

• Find the area of the Triangle

A ½ bh
A (½) (7) (8) 28 units2
Try it when b 15 and h 12
A ½ bh (½) (15) (12) 90 units2
7
Area of 45-45-90 Triangles
The area of a 45-45-90 right triangle is one half
of its leg length squared.
A ½ s2
8
Example 4
37.5 cm2
9
Area of 30-60-90 Triangles
The area of a 30-60-90 right triangle is
10
Example 5
Find the area of the 30-60-90 right triangle.
Leave your answer in simple radical form.
11
Area of Trapezoids
The area of a Trapezoid is half the product of
the height and the sum of the two bases.
12
Example 6