Question

the radius of circle e is 10 centimeters.

what is the diameter of circle e? what is the circumference of circle e? what is the area of circle e?

use the given information to complete the worksheet. use 3.14 as an approximation for \\( \pi \\).

radius of circle e
diameter of circle e
circumference of circle e
area of circle e

area formulas:

• parallelogram: \\( a = bh \\)
• square: \\( a = s^2 \\)
• triangle: \\( a = \frac{1}{2} bh \\)
• trapezoid: \\( a = \frac{1}{2} h(b_1 + b_2) \\)
• circle: \\( a = \pi r^2 \\)

Explanation:

Step1: Find the diameter of Circle E

The diameter \( d \) of a circle is twice the radius \( r \), so \( d = 2r \). Given \( r = 10 \) cm, we have \( d = 2\times10 = 20 \) cm.

Step2: Find the circumference of Circle E

The formula for the circumference \( C \) of a circle is \( C = 2\pi r \) (or \( C=\pi d \)). Using \( \pi\approx3.14 \) and \( r = 10 \) cm, we get \( C = 2\times3.14\times10 = 62.8 \) cm.

Step3: Find the area of Circle E

The formula for the area \( A \) of a circle is \( A=\pi r^{2} \). Using \( \pi\approx3.14 \) and \( r = 10 \) cm, we have \( A = 3.14\times10^{2}=3.14\times100 = 314 \) square cm.

Answer:

• Radius of Circle E (EF): 10 centimeters
• Diameter of Circle E: 20 centimeters
• Circumference of Circle E: 62.8 centimeters
• Area of Circle E: 314 square centimeters