Circumference of Circles

What is the distance around a circle?

• Circumference
• Area
• Diameter
• Radius

The radius of a circle is ​ (a)   the diameter.

• half
• twice
• triple

Match the formulas to the measurements indicated.

• To find the radius of the circle use:

• To find the circumference of a circle use:

• 2r

• To find the diameter of a circle use:

• To find the area of a circle use:

What is the length of the diameter of the circle?

12 inches in this circle represents its

• radius

• diameter

Alex has trained his puppy, Popper, to jump through a ring. According to Alex's measurements and calculations, the ring has a diameter of 3.5 feet. What is the ring's circumference (use 3.14 for pi)?

• 11.32 ft
• 12.25 ft
• 10.99 ft
• 8.75 ft

What is the EXACT AREA of this circle? (HINT: Write in terms of pi)

Mathematical Equivalence

ON

What is the area of this circle?

• 1385.44
• 2142.12
• 5541.77
• 1289.12