U10F4

Last updated almost 5 years ago

3 questions

Find the Area of a Regular Pentagon with a side of 10 cms? Answer each part.

1

What is the central angle in a regular pentagon. Remember the Central Angle is 360/n where n is the sides of a pentagon.

90

72

60

45

5/tan36

5*tan36

5*cos36

5*sin36

345 cm2

34.5 cm2

172.5 cm2

6.9 cm2

What is the central angle in a regular pentagon. Remember the Central Angle is 360/n where n is the sides of a pentagon. 

90

72

60

45

Find the Apothem a (perpendicular to the base) for the Central Triangle shown below: Remember SOH CAH TOA

5/tan36

5*tan36

5*cos36

5*sin36

Given that the Apothem a = 6.9 cm and the Area A = 1/2 * a * P where P is the Perimeter, select A?

345 cm2

34.5 cm2

172.5 cm2

6.9 cm2