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3 years ago

What's the area of a circle with diameter 18 units? Question 8 options: A) 9π units2 B) 81π units2 C) π units2 D) 18π units2

Mathematics

1 answer:

Anna [14]3 years ago

6 0

Answer:

B) 81π units²

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS

Brackets
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction

Left to Right

Geometry

Radius of a Circle Formula: r = d/2

r is radius
d is diameter

Area of a Circle Formula: A = πr²

Step-by-step explanation:

Step 1: Define

Diameter d = 18 units

Step 2: Manipulate Variables

Radius r = 18 units/2 = 9 units

Step 3: Find Area

Substitute in r [Area of a Circle Formula]: A = π(9 units)²
[Area] Evaluate exponents: A = π(81 units²)
[Area] Multiply: A = 81π units²

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