Understanding Circles: Radius and Diameter

In this video, Mr. J explains the concepts of radius and diameter in circles. He begins with an introduction to the topics and then delves into the definitions and examples of radius and diameter. The video covers how to calculate the radius when given the diameter and vice versa. Mr. J provides clear examples and explanations to help viewers understand these fundamental concepts in geometry. The video concludes with a summary of the key points discussed.

What are the two main topics discussed in the video?

• Diameter and Area

• Radius and Diameter

• Radius and Circumference

• Circumference and Area

What is the radius of a circle?

• The distance from the center to any point on the edge

• The distance across the circle through the center

• The distance around the circle

• The distance from one edge to another without passing through the center

If the radius of a circle is 3 inches, what is the diameter?

• 3 inches

• 6 inches

• 9 inches

• 12 inches

What is the diameter of a circle?

• The distance around the circle

• The distance across the circle through the center

• The distance from one edge to another without passing through the center

• The distance from the center to any point on the edge

If the diameter of a circle is 4 centimeters, what is the radius?

• 1 centimeter

• 2 centimeters

• 4 centimeters

• 3 centimeters

How do you find the radius if you know the diameter?

• Divide the diameter by 2

• Subtract 2 from the diameter

• Multiply the diameter by 2

• Add 2 to the diameter

If a circle has a diameter of 8 feet, what is its radius?

• 6 feet

• 4 feet

• 2 feet

• 8 feet

How do you find the diameter if you know the radius?

• Divide the radius by 2

• Multiply the radius by 2

• Add 2 to the radius

• Subtract 2 from the radius

If a circle has a radius of 10 inches, what is its diameter?

• 15 inches

• 10 inches

• 25 inches

• 20 inches

What is the relationship between the radius and diameter of a circle?

• The radius is twice the diameter

• The diameter is twice the radius

• The radius is half the circumference

• The diameter is half the circumference