Calculating Area and Circumference of Circles

This video tutorial provides an overview of circles, focusing on key concepts such as radius, diameter, circumference, and area. It explains how to calculate the circumference and area of a circle, and how to determine the radius and diameter from given values. The tutorial includes examples and emphasizes the importance of understanding these fundamental geometric concepts.

What is the diameter if the radius of a circle is 8 units?

• 16 units

• 4 units

• 8 units

• 32 units

If the diameter of a circle is 14 units, what is its radius?

• 7 units

• 28 units

• 21 units

• 14 units

Which formula can be used to calculate the circumference of a circle?

• C = πd

• C = πr^2

• C = 2πr

• Both A and B

How is the circumference of a circle directly related to its diameter?

• C = πd

• C = d^2

• C = d/π

• C = π/d

If the circumference of a circle is 31.4 units, what is the radius?

• 5 units

• 10 units

• 15 units

• 20 units

If a circle's circumference is 62.8 units, what is its diameter?

• 40 units

• 20 units

• 30 units

• 10 units

What is the area of a circle with a radius of 7 units?

• 44 units^2

• 154 units^2

• 88 units^2

• 22 units^2

What is the formula to calculate the area of a circle?

• A = πr^2

• A = 2πr

• A = πd

• A = πr

Given an area of 78.5 square units, what is the approximate radius of the circle?

• 10 units

• 5 units

• 20 units

• 15 units

Given an area of 314 square units, what is the diameter of the circle?

• 10 units

• 40 units

• 20 units

• 30 units