Proportionality of Circles

Does there appear to be a proportional relationship between the radius and circumference of a circle? Explain your reasoning.

• Yes, the points line up on a straight line that leads back to the origin.

• Yes, there is a Constant of Proportionality.

• No, the points line up on a straight line, but do not include the origin.

• No, there isn't a Constant of Proportionality.

Tags

CCSS.7.RP.A.2D

Select all of the true statements.

Tags

CCSS.7.G.B.4

A groundskeeper needs grass seed to cover a circular field, 290 feet in diameter.

A Store sells 50-pound bags of grass seed that covers about 20,000 square feet of field.

What is the least number of WHOLE bags the groundskeeper must buy to cover the circular field?

What is the constant of proportionality between the circumference and the diameter?

• π, or 3.14

• It depends on the measurements.

• They are not proportional.

• 2π, or 6.28

Answer explanation

When we divide the circumference by the diameter, we always get π.

Tags

CCSS.7.RP.A.2B

Which shows the ratio for pi?

• circumference to diameter

• radius to circumference

• area to diameter

• area to radius

Tags

CCSS.7.G.B.4

The ratio of the radii of two circles is 4:9. What is the ratio of their circumferences?

• 2:3

• 4:9

• 16:81

Tags

CCSS.7.G.B.4

The ratio of the circumference of a circle to the diameter

• distance

• pi

• radii

• diameter

Tags

CCSS.7.G.B.4

is the Constant of Proportionality between the circumference and diameter of any circle.

• Diameter

• Circumference

• Radius

• Pi

Tags

CCSS.7.G.B.4

What is the constant of proportionality relating the circumference and the diameter of a circle?

Mathematical Equivalence

ON

Tags

CCSS.7.G.B.4

Which graph correctly relates diameter and circumference?

• 
• 
• 
• 

Tags

CCSS.8.EE.B.5