Quiz on Areas of Circles and Sectors

What is the formula for the area of a circle?

• πd

• πr²

• 2πr

• 2πr²

If the diameter of an umbrella is 72 inches, what is the radius of the circular cover that is 8 inches longer on each side?

• 52 inches

• 40 inches

• 44 inches

• 36 inches

Why is it important to leave answers in terms of pi when calculating areas?

• To simplify the formula

• To make calculations easier

• To avoid using calculators

• To ensure exact answers

How do you find the radius of a circle if the area is given as 58 square inches?

• Divide 58 by π and take the square root

• Multiply 58 by 2π

• Divide 58 by 2π

• Multiply 58 by π and take the square root

What is a sector of a circle?

• A rectangle

• A line segment

• A piece of a circle

• A full circle

How do you calculate the area of a sector?

• Divide the radius by the central angle

• Multiply the central angle by πr²

• Divide the central angle by 360 and multiply by πr²

• Multiply the radius by the central angle

If a pie has a diameter of 9 inches and is cut into 10 slices, what is the radius of the pie?

• 4.5 inches

• 9 inches

• 4 inches

• 3 inches

What is the area of one slice of pie if the pie is cut into 10 equal slices?

• 7.36 square inches

• 8.36 square inches

• 6.36 square inches

• 5.36 square inches

To what decimal place should the area of a slice of pie be rounded?

• Nearest hundredth

• Nearest thousandth

• Nearest whole number

• Nearest tenth

What is the central angle of a sector if the circle is divided into 10 equal parts?

• 60 degrees

• 30 degrees

• 45 degrees

• 36 degrees