1. Areas of Triangles, Quadrilaterals, and Circles
By: Mr. Sheldon

2. Area of a Triangle 𝐴𝑟𝑒𝑎= 1 2 𝑏ℎ b=Length of an Base
h=Height or Length of an Altitude

3. Area of a Rectangle 𝐴𝑟𝑒𝑎=𝑙𝑤 𝑙= length of the rectangle
w= width of rectangle

4. Area of a Square
𝐴𝑟𝑒𝑎= 𝑙 2
𝑙=length of any one side of the square

5. Area of a Parallelogram
𝐴𝑟𝑒𝑎=𝑏ℎ
𝑏=length of a base
ℎ=length of the height

6. Area of a Trapezoid 𝐴𝑟𝑒𝑎= 1 2 𝑏 1 + 𝑏 2 ℎ 𝑏 1 = length of one base
𝐴𝑟𝑒𝑎= 𝑏 1 + 𝑏 2 ℎ
𝑏 1 = length of one base
𝑏 2 = length of the opposite base
ℎ=height of the trapezoid

7. Circumference of a Circle
𝐶=2π𝑟
𝑟=radius of the circle π≈
Always give in terms of π before giving a decimal answer

8. Area of a Circle 𝐴=𝜋 𝑟 2 𝑟=radius of the circle π≈3.14159
Always give in terms of π before giving a decimal answer

9. Assignment
Worksheet over area of triangles and quadrilaterals