Finding the Radius from the Diameter

In this video, Mr. J explains how to find the radius of a circle when given the diameter. He begins by defining the diameter as a line segment that passes through the center of the circle, dividing it into two equal parts. The radius is then described as half the diameter, extending from the center to any point on the circle. Mr. J provides two examples: one with a diameter of 8 feet, resulting in a radius of 4 feet, and another with a diameter of 33 meters, resulting in a radius of 16.5 meters. The video concludes with a summary of the method: divide the diameter by two to find the radius.

What is the diameter of a circle?

• The area of the circle

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

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

• The distance around the circle

Tags

CCSS.HSG.C.A.2

How do you find the radius of a circle if you know the diameter?

• Square the diameter

• Subtract 2 from the diameter

• Multiply the diameter by 2

• Divide the diameter by 2

Tags

CCSS.7.G.B.4

What is the formula to calculate the radius from the diameter?

• Radius = Diameter - 2

• Radius = Diameter + 2

• Radius = Diameter * 2

• Radius = Diameter / 2

Tags

CCSS.7.G.B.4

What does the diameter of a circle represent?

• The distance around the circle

• The length from the center to the edge of the circle

• A line segment through the center connecting two points on the circle

• The total area of the circle

How is the radius related to the diameter?

• There is no relation

• The radius is half of the diameter

• The radius is the same as the diameter

• The radius is double the diameter

Tags

CCSS.7.G.B.4

What is the radius of a circle with a diameter of 16 meters?

• 4 meters

• 32 meters

• 16 meters

• 8 meters

Tags

CCSS.7.G.B.4

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

• 2 feet

• 4 feet

• 16 feet

• 8 feet

Tags

CCSS.7.G.B.4

What unit of measurement was used in example 1?

• Centimeters

• Inches

• Feet

• Meters

Tags

CCSS.2.MD.A.2

If the diameter of a circle is 33 meters, what is the radius?

• 66 meters

• 33 meters

• 16.5 meters

• 8.25 meters

Tags

CCSS.7.G.B.4

In example 2, what is the radius in meters?

• 16.5 meters

• 33 meters

• 15 meters

• 32 meters

Tags

CCSS.7.G.B.4