• interior angle

• equilateral• equiangular• regular polygon

• Find the sum of the angle measures of a polygon and the measure of an interior angle of a regular polygon.

Find the Sum of Interior Angle Measures

ALGEBRA Find the sum of the measures of the interior angles of a hexagon.

Answer: The sum of the measures of the interior angles of a hexagon is 720.

S = (n – 2)180 Write an equation.

S = (6 – 2)180 Replace n with 6.

S = (4)180 or 720 Simplify.

1. A

2. B

3. C

4. D0% 0%0%0%

A. 540

B. 720

C. 810

D. 900

ALGEBRA Find the sum of the measures of the interior angles of a heptagon (7-sided figure).

DESIGN A designer is creating a new logo for a bank. The logo consists of a regular pentagon surrounded by isosceles triangles. Find the measure of an interior angle of a pentagon.

A pentagon has 5 sides.

Step 1 Find the sum of the measures of the angles.

S = (n – 2)180 Write an equation.

S = (5 – 2)180 Replace n with 5.

S = (3)180 or 540 Simplify.

The sum of the measures of the interior angles of a regular pentagon is 540.

Step 2 Divide 540 by 5, the number of interior angles, to find the measure of one interior angle. So, the measure of one interior angle of a regular pentagon is 540 ÷ 5 or 108.

Answer: 108°

1. A

2. B

3. C

4. D0% 0%0%0%

A. 108°

B. 122°

C. 140°

D. 148°

DESIGN Michelle is designing a new logo for the math club. She wants to use a regular nonagon as part of the logo. Find the measure of an interior angle of a nonagon.

1. A

2. B

3. C

4. D0% 0%0%0%

A. 11 balloons

B. 22 balloons

C. 44 balloons

D. 66 balloons

A party store is having a sale on balloons. The balloons cost $0.35 per balloon, but if you purchase 4, you get 2 free. If Suzie spent $15.40 (before adding sales tax), how many balloons did she get for free? Use logical reasoning.

(over Lesson 6-2)

1. A

2. B

3. C

4. D0% 0%0%0%

A. 11 balloons

B. 22 balloons

C. 44 balloons

D. 66 balloons

A party store is having a sale on balloons. The balloons cost $0.35 per balloon, but if you purchase 4, you get 2 free. If Suzie spent $15.40 (before adding sales tax), how many balloons did she get total? Use logical reasoning.

(over Lesson 6-2)

1. A

2. B

3. C

4. D0% 0%0%0%

A. 10 floats

B. 20 floats

C. 30 floats

D. 40 floats

While watching a parade, Sabrina noticed that after every 5 floats, a marching band passed by. Use logical reasoning to determine how many floats Sabrina has seen if she is listening to the sixth marching band.

(over Lesson 6-2)

1. A

2. B

3. C

4. D0% 0%0%0%

A. 743 mm

B. 7,430 mm

C. 743,000 mm

D. 7,430,000 mm

If 22 millimeters equals 0.022 meter and 0.022 meter equals 0.000022 kilometer, then how many millimeters are in 7.43 kilometers? Use logical reasoning.

(over Lesson 6-2)