Understanding Circle Diameters and Radii

In this video, Mr. J explains how to find the diameter of a circle when given the radius. He begins by defining the radius as the distance from the center of the circle to any point on the circle, and the diameter as a line segment that passes through the center, connecting two points on the circle. The diameter is twice the length of the radius. Mr. J demonstrates this concept with two examples: one with a radius of 7 inches, resulting in a diameter of 14 inches, and another with a radius of 24 centimeters, resulting in a diameter of 48 centimeters. The video concludes with a summary of the method for calculating the diameter from the radius.

What is the radius of a circle?

• A line segment from the center to any point on the circle

• A line segment that goes through the center and connects two points on the circle

• The area of the circle

• The circumference of the circle

How does the diameter of a circle relate to its radius?

• The diameter is equal to the radius

• The diameter is three times the radius

• The diameter is half the radius

• The diameter is twice the radius

If the radius of a circle is 7 inches, what is the diameter?

• 28 inches

• 14 inches

• 7 inches

• 21 inches

In Example 1, what operation is used to find the diameter from the radius?

• Addition

• Subtraction

• Multiplication

• Division

What is the diameter of a circle with a radius of 24 centimeters?

• 24 centimeters

• 36 centimeters

• 48 centimeters

• 60 centimeters

In Example 2, what is the first step to find the diameter?

• Subtract the radius from itself

• Divide the radius by 2

• Multiply the radius by 2

• Add the radius to itself

What is the final step in calculating the diameter in Example 2?

• Divide the result by 2

• Subtract the radius from the result

• Add the radius to the result

• Write the result as the diameter

What is the purpose of the video tutorial?

• To demonstrate how to draw a circle

• To explain how to find the diameter of a circle given the radius

• To teach how to calculate the area of a circle

• To show how to measure the circumference of a circle

What is the key takeaway from the video?

• The diameter is three times the radius

• The diameter is half the radius

• The diameter is equal to the radius

• The diameter is twice the radius

What should you do if you know the radius and need to find the diameter?

• Multiply the radius by 2

• Subtract 2 from the radius

• Divide the radius by 2

• Add 2 to the radius