Circles and Circumference

Find the diameter and radius of a circle with a Circumference of 40 in.

• d = 20 in

  r = 10 in

• r = 12.73 in

  d = 6.37 in

• d = 7.14 in

  r = 3.57 in

• d = 12.73 in

  r = 6.37 in

What is the radius of a circle?

• The radius of a circle is the circumference of the circle divided by 2.

• The radius of a circle is a line segment that connects the center of the circle to any point on the circle. It is half the diameter of the circle.

• The radius of a circle is a straight line that connects two points on the circle.

• The radius of a circle is always equal to the diameter of the circle.

If the diameter of a circle is 12 units, what is the radius of the circle?

• 8

• 6

• 4

• 10

What is the diameter of a circle with a radius of 9 units?

• 81

• 27

• 18

• 12

If the circumference of a circle is 31.4 units, what is the radius of the circle? (Use π = 3.14)

• 5

• 7

• 3

• 10

What is the formula to find the radius of a circle given its diameter?

• radius = diameter - 2

• radius = diameter / 2

• radius = diameter * 2

• radius = diameter + 2

The diameters of Circle L and Circle M are 20 and 13 units respectively.

QR= 4, FInd RM.

• 2.5

• 6.5

• 2

• 3.5

The diameters of Circle L and Circle M are 20 and 13 units respectively. QR = 4, FInd LQ.

What is the center of a circle?

• The center of a circle is a line segment.

• The center of a circle is a square.

• The center of a circle is a single point.

• The center of a circle is a triangle.

How do you name a circle using its center when the radii are BT and BY?

• Circle B

• Circle BT

• Circle BTY

• Circle BY