Sector Area and Arc Length in Circles Unit 11: Circles Sector Area and Arc Length in Circles Objectives 4/20/12 & 4/23/12 Find the area of sectors. Find arc lengths. *Standard 21.0: Students prove and solve problems regarding relationships among chords, secants, tangents, inscribed angles, and inscribed and circumscribed polygons of circles.

Sector Area and Arc Length in Circles Unit 11: Circles Sector Area and Arc Length in Circles Vocabulary sector of a circle segment of a circle arc length *Standard 21.0: Students prove and solve problems regarding relationships among chords, secants, tangents, inscribed angles, and inscribed and circumscribed polygons of circles.

The area of a sector is a fraction of the circle containing the sector The area of a sector is a fraction of the circle containing the sector. To find the area of a sector whose central angle measures m°, multiply the area of the circle by

A segment of a circle is a region bounded by an arc and its chord. Write the degree symbol after m in the formula to help you remember to use degree measure not arc length. Helpful Hint A segment of a circle is a region bounded by an arc and its chord.

In the same way that the area of a sector is a fraction of the area of the circle, the length of an arc is a fraction of the circumference of the circle.

**Examples: Finding the Area of a Sector 1. Find the area of sector HGJ. Give answers in terms of 

**Examples: Finding the Area of a Sector 2. Find the area of sector ABC. Give answers in terms of 

**Examples: Finding the Area of a Sector 3. Find the area of sector ACB. Give your answer in terms of 

**Examples: Finding the Area of a Sector 4. Find the area of sector JKL. Give your answer in terms of 

**Examples: Finding the Area of a Segment 5. Find the area of segment LNM and simplify your answer as much as possible.

**Examples: Finding the Area of a Segment 6. Find the area of segment RST and simplify your answer as much as possible.

**Examples: Finding Arc Length 7. Find the length of . Give your answer in terms of  FG

**Examples: Finding Arc Length 8. Find the length of . Give your answer in terms of  GH

**Examples: Finding Arc Length 9. Find the length of an arc with measure 135° in a circle with radius 4 cm. Give your answer in terms of 