Question

What's the circumference of a
circle with a diameter of 22 inches? (use 3.14 for pi)

Answer 1

69.08

Explanation:

circumference is pi times diameter

22×3.14=69.08 inches

Answer 2

C = 69.08 in

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS

1. Brackets
2. Parenthesis
3. Exponents
4. Multiplication
5. Division
6. Addition
7. Subtraction

• Left to Right

Equality Properties

Geometry

• Radius: r = d/2
• Circumference: C = 2πr

Explanation:

Step 1: Define

d = 22 in

Step 2: Find r

1. Substitute: r = 22 in/2
2. Divide: r = 11 in

Step 3: Find C

1. Substitute: C = 2π(11 in)
2. Multiply: C = 22π in
3. Multiply: C = 69.08 in