Posted by **cindy** on Thursday, January 12, 2012 at 5:59pm.

Find the area of a regular pentagon with a side of 6 ft. Give the answer to the nearest tenth.

ok can't remember how to do this

- geometry -
**Reiny**, Thursday, January 12, 2012 at 6:31pm
A regular pentagon can be drawn as 5 conguent isosceles triangles with a central angle of 72° each, and equal base angles of 54°.

So just find the area of one of these by first finding the altitude of one of them

tan 54° = h/3

h = 3tan54°

area of one of them = (1/2)base x height

= (1/2)(6)(3tan54)

= 9tan 54°

so the whole pentagon = 45tan 54°

= appr. 61.9 square ft

- geometry -
**Shay**, Thursday, January 12, 2012 at 6:33pm
You forgot to give us the lenght of the side of the line that connects from the middle of the pentagon to a side of the pentagon.

- geometry -
**Steve**, Friday, January 13, 2012 at 12:00am
It's there; you just need to recognize it:

h = 3tan54°

## Answer this Question

## Related Questions

- geometry - Find the area of a regular pentagon with a side of 6ft. answer ...
- Geometry - Find the area of a regular pentagon with a side of 6ft. Give the ...
- geometry - What is the area of a regular pentagon with a side length of 10 ...
- geometry - find the area bounded by a regular pentagon with radius 6 cm. round ...
- Geometry - Find the area of a regular pentagon with radius 3cm. Round to the ...
- Geometry - Hi, I'm having a difficult time understanding a couple of Geometry ...
- geometry - 1.what is the area of a sector with a central angle of 160 degrees ...
- geometry - find the area of a regular hexagon with the side length 4m. round to ...
- Geometry - Find the area of a regular hexagon with side length of 10 centimeters...
- Geometry - Area - Find the area of a regular hexagon with an apothem 10.4 yards ...

More Related Questions