Areas and Perimeter of Regular Polygons and Circles

A regular pentagon has side length 4 in. What is its perimeter?

• 20 in

• 10 in

• 12 in

• 40 in

Which is false?

• The perimeters of similar regular polygons are in proportion.

• The areas of similar regular polygons are in proportion.

• The sides of similar regular polygons are in proportion.

• None of the others are false.

Two similar polygons have side lengths in the ratio of 2/3. What is the ratio of their perimeters?

• 2/3

• 4/9

• It depends on the side lengths.

• It depends on how many sides there are.

How do you find the area of a regular n-gon (if n is greater than 4)?

• A = .5ans

• A = b*h

• Depends on the shape of the regular n>4-gon.

Find the area of a regular  dodecagon with a perimeter of 144 cm.

• 1247 cm²

• 1523 cm²

• 1612.2 cm²

• 1845 cm²

What is the circumference of a circle?

Area of a circle. Which is not right?

Two similar polygons have side lengths in the ratio of 2/3. What is the ratio of their areas?

• 2/3

• 4/9

• It depends on the side lengths.

• It depends on how many sides there are.

A regular pentagon has side length 5 and apothem 5. What is its area?

• 62.5

• 125

• 25

• 12.5

A circle has a radius of 8. What is its diameter?

• 4

• 8

• 16

• They're unrelated