Understanding Circles: Area and Circumference

What is the formula for the area of a circle?

• PI diameter

• PI R squared

• R squared / PI

• 2 PI R

How do you calculate the area of a circle with a radius of 9 inches?

• 81 PI inches squared

• PI 9 squared inches

• 18 PI inches squared

• 9 PI inches squared

What formula can be used to calculate the circumference of a circle using its diameter?

• PI diameter

• 2 PI R

• R / PI

• PI R squared

Which of the following is a correct representation of the circumference formula?

• 2 R / PI

• 2 PI R

• PI R squared

• R squared / PI

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

• 58 PI yards

• 29 PI yards

• 116 yards

• 182.21 yards

How do you find the diameter of a circle if its circumference is given as 65.97 meters?

• Divide by 2 PI

• Square the circumference

• Multiply by PI

• Divide by PI

What is the radius of a circle if its area is 530.93 square feet?

• 7 feet

• 14 feet

• 26 feet

• 13 feet

How can you find the area of a circle given its circumference?

• Multiply the circumference by PI

• Use the circumference to find the radius first

• Divide the circumference by PI

• Square the circumference

What is the first step in finding the area of a circle if you know its circumference?

• Find the radius

• Square the circumference

• Multiply by PI

• Divide by 2 PI

If the area of a circle is 289 PI square millimeters, what is its radius?

• 289 millimeters

• 144.5 millimeters

• 17 millimeters

• 34 millimeters