Geometry worked example
Calculate the area of a circle with radius 7
Apply A = πr² to a circle with radius 7 and find both the exact and approximate area.
Question
What is the area of a circle with radius 7?
Step-by-step solution
The area of a circle depends on its radius. Use A = πr², where r is the distance from the center to the edge.
Step 1: Substitute the radius
Here r = 7, so A = π(7)².
Step 2: Square and simplify
7² = 49, giving A = 49π square units. This is the exact answer.
Step 3: Approximate if needed
Using π ≈ 3.14159, 49π ≈ 153.94 square units.
If the radius is measured in centimeters, the area is 49π cm², or approximately 153.94 cm². Remember to square the length unit when reporting area.
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