Quiz on Areas of Circles and Sectors

What is the formula for calculating the area of a circle?

• Area = 2πr

• Area = πr²

• Area = πd

• Area = 2πd

If the diameter of a circle is 20 meters, what is the radius?

• 20 meters

• 15 meters

• 10 meters

• 5 meters

How do you find the radius if you know the area of a circle?

• Divide the area by 2π

• Divide the area by π and then take the square root

• Multiply the area by π and then take the square root

• Multiply the area by 2π

What is the radius of a circle if its area is 153.9 square centimeters?

• 6 cm

• 7 cm

• 8 cm

• 9 cm

If a circle's area is given as 283.5 inches squared, what is the radius?

• 9.5 inches

• 11.5 inches

• 10.5 inches

• 8.5 inches

What is the diameter of a circle if its radius is 7 inches?

• 28 inches

• 21 inches

• 14 inches

• 7 inches

What is the formula for the area of a sector of a circle?

• Area = (x/360) × πr²

• Area = (x/180) × πr²

• Area = (x/360) × 2πr

• Area = (x/180) × 2πr

If a sector of a circle has an angle of 45 degrees and a radius of 3 feet, what is the area of the sector?

• 5.5 feet²

• 4.5 feet²

• 6.5 feet²

• 3.5 feet²

How many degrees are in a full circle?

• 180 degrees

• 360 degrees

• 90 degrees

• 270 degrees

If a circle is divided into three equal sectors, what is the angle of each sector?

• 180 degrees

• 90 degrees

• 120 degrees

• 240 degrees