Mastering Circles: Radius and Diameter Explained

In this video, Mr. J explains the concepts of radius and diameter in circles. He provides definitions and examples for both terms, illustrating how the radius is the distance from the center to the edge of a circle, while the diameter is a line passing through the center from one edge to the other. The video also covers how to calculate the radius if given the diameter and vice versa, emphasizing that the radius is half the diameter and the diameter is twice the radius.

What are the two main topics discussed in the video?

• Radius and Circumference

• Radius and Diameter

• Circumference and Area

• Diameter and Area

How is the radius of a circle defined?

• 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

In the example given, what is the radius of the circle?

• 2 inches

• 4 inches

• 3 inches

• 5 inches

How is the diameter of a circle defined?

• The distance around the circle

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

• The distance across the circle through the center

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

In the example given, what is the diameter of the circle?

• 3 centimeters

• 5 centimeters

• 2 centimeters

• 4 centimeters

What is the relationship between the radius and diameter?

• The diameter is half the circumference

• The radius is twice the diameter

• The diameter is twice the radius

• The radius is half the circumference

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

• 4 feet

• 8 feet

• 16 feet

• 2 feet

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

• 20 inches

• 5 inches

• 15 inches

• 10 inches

What operation is used to find the diameter from the radius?

• Addition

• Subtraction

• Multiplication

• Division

What operation is used to find the radius from the diameter?

• Multiplication

• Subtraction

• Addition

• Division