Question

1. how do you calculate the area of a circle?

a. ( a = 2pi r )
b. ( a = pi r^{2} )
c. ( a = pi d^{2} )
d. ( a = pi(2r) )

Explanation:

Step1: Recall the formula for the area of a circle

The formula for the area of a circle is \(A = \pi r^{2}\), where \(r\) is the radius of the circle.

Step2: Analyze each option

• Option a: \(A = 2\pi r\) is the formula for the circumference of a circle, not the area.
• Option b: \(A=\pi r^{2}\) is the correct formula for the area of a circle.
• Option c: If \(d\) is the diameter (\(d = 2r\)), then \(A=\pi d^{2}/4

eq\pi d^{2}\).

• Option d: \(A=\pi(2r)=2\pi r\) is also the formula for the circumference of a circle.

Answer:

B. \(A = \pi r^{2}\)