Area when given radius
What is the number we use for pi?
3.14
What is the formula for the area of a circle?
A = pi x radius x radius
What are the formulas for finding circumference?
C = 2 x pi x radius and C = diameter x pi
What is the DIAMETER of a circle that has a radius of 5 inches?
diameter = 10 inches
What is the area of a circle with a radius of 7 ft?
153.86 ft2
When finding the area of a circle and you are given the DIAMETER, what do you do first?
Find the radius.
Andrea bought a new circular dining room table with a radius of 2 feet. She wants to decorate the outer edge of the table with wooden beads. What is the distance around the outer edge of the table?
12.56 feet
What is the RADIUS of a circle with a 28 cm diameter?
radius = 14 cm
What is the area of a circle with a 8 mm radius?
200.96 mm2
What is the area of a circle with a diameter of 6 cm?
28.26 cm2
You buy a new wheel for your bicycle. The diameter of the bicycle wheel is 22 inches. What is the circumference of the bicycle wheel?
69.08 inches
What is the DIAMETER of a circle that has a radius of 7.5 inches?
diameter = 15 inches
What is the area of a circle with a 2.5 cm radius?
19.625 cm2
What is the area of a circle with a diameter of 12 inches?
113.04 in2
Marco runs laps at the local high school. It is a circular track with a diameter of 45 feet. How far does he run after completing one lap?
141.3 ft
What is the RADIUS of a circle with a 9 cm diameter?
radius = 4.5 cm
What is the area of the circle with a 4.5 inch radius?
63.585 in2
What is the area of a circle with a diameter of 24 mm?
452.16 mm2
You collect coins. One of your favorite coins is a silver-colored coin showing a man’s portrait. The radius of the coin is 12 millimeters. What is the circumference of the coin?
75.36 mm
True or False: The diameter goes from edge to edge, through the center of a circle.
True