Circle Geometry Concepts and Calculations

This video tutorial covers the formulas for calculating the area and circumference of circles. It emphasizes the importance of using the pi symbol for accuracy in calculations and provides examples of how to compute these values. The tutorial also explains how to find the radius or diameter from given measurements and concludes with practice problems to reinforce the concepts.

Why is it important to use the pi symbol instead of 3.14 in calculations?

• Because pi is a variable

• Because 3.14 is not a number

• Because pi is easier to type

• Because 3.14 is not accurate enough

Tags

CCSS.7.G.B.4

What is the formula for the area of a circle?

• 2 * pi * radius

• pi * diameter

• pi * radius^2

• 2 * pi * diameter

Tags

CCSS.7.G.B.4

If the radius of a circle is 12, what is the area?

• 144 * pi

• 144

• 12 * pi

• 24 * pi

Tags

CCSS.7.G.B.4

What is the formula for the circumference of a circle?

• pi * radius

• pi * diameter^2

• 2 * pi * radius

• pi * radius^2

Tags

CCSS.7.G.B.4

If the diameter of a circle is 58, what is the circumference?

• 116 * pi

• 29 * pi

• 58

• 58 * pi

Tags

CCSS.7.G.B.4

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

• Multiply the circumference by 2

• Divide the circumference by pi

• Divide the circumference by 2

• Multiply the circumference by pi

Tags

CCSS.7.G.B.4

If the circumference of a circle is 21.99 feet, what is the radius?

• 21.99 * pi

• 21.99 * 2

• 21.99 / (2 * pi)

• 21.99 / pi

Tags

CCSS.7.G.B.4

If the area of a circle is 380.13, what is the radius approximately?

• 11

• 14

• 12

• 13

Tags

CCSS.7.G.B.4

How do you find the area of a circle if you know the circumference?

• Use the radius derived from the circumference

• Use the diameter derived from the circumference

• Multiply the circumference by pi

• Divide the circumference by pi

Tags

CCSS.7.G.B.4

If the circumference of a circle is 26 pi feet, what is the area?

• 26 * pi

• 13 * pi

• 169 * pi

• 169

Tags

CCSS.7.G.B.4