Exploring Circumference and Area of Circles

What is the term used to describe the distance across a circle through its center?

• Area

• Radius

• Diameter

• Circumference

What is the formula for the circumference of a circle when given the diameter?

• C = 2d

• C = 2πr

• C = πd

• C = πr²

If the diameter of a circle is 10 inches, what is the circumference using Pi (π) as 3.14?

• 20.7 inches

• 15.7 inches

• 62.8 inches

• 31.4 inches

Using the formula C = 2πr, find the circumference if the radius is 24 inches.

• 48 inches

• 100.6 inches

• 75.4 inches

• 150.8 inches

How many times does a bug travel the circumference of a 150.8 inch circle if it completes 5 rotations?

• 755 inches

• 752 inches

• 754 inches

• 753 inches

Calculate the distance around a track that includes two straight lengths of 84.39 meters and two semicircles with a diameter of 73 meters each.

• 400.00 meters

• 398.12 meters

• 396.78 meters

• 395.44 meters

What is the perimeter of a rectangle that is 8 inches by 10 inches?

• 40 inches

• 20 inches

• 36 inches

• 18 inches

What is the new perimeter of the track if the width is increased by 9.76 meters on both sides?

• 457.76 meters

• 458.88 meters

• 459.44 meters

• 460.00 meters

If a wire frame shaped into a circle has a circumference of 36 inches, what is its radius?

• 5.73 inches

• 3.14 inches

• 11.46 inches

• 18 inches

If the area of a rectangle is subtracted by the area of a triangle to estimate a floor plan, what is this method called?

• Geometric deduction

• Area approximation

• Subtraction estimation

• Composite area method