Parts of a Circle

Section 10.5
Areas of Circles and Sectors

Area of A Circle

Example

How much more pizza is in a 12-in diameter pizza than in a 10-in diameter pizza?

Multiple Choice

How much more pizza is in a 14-in diameter pizza than in a 12-in pizza? Round to the nearest whole number

• 2 in²

• 41 in²

• 14 in²

• 35 in²

Sectors

Area of a Sector of a Circle

Finding the Area of a Sector of a Circle

Find the area of sector ZOM.

Multiple Choice

A circle has a diameter of 20 cm. What is the area of a sector bounded by a 208° major arc? Round to the nearest tenth.

• 181.5cm²

• 41.6 cm²

• 200.7 cm²

• 208 cm²

Segment of a circle

A part of a circle bounded by an arc and the segment joining its endpoints is a segment of a circle

To find the area of a segment of a circle, draw a radii to form a sector. The area of the segment equals the area of the sector minus the area of the triangle formed.

Finding the Area of a Segment of a circle

Find the area of the shaded segment. Round your answer to the nearest tenth.

Multiple Choice

A circle has a radius of 12 cm. Find the area of the smaller segment of the circle determined by a 60° arc. Round your answer to the nearest tenth.

• 13.7 cm²

• 15.6 cm²

• 20 cm²

• 13.0 cm²

Homework

10.5 - In formative