Wednesday

September 17, 2014

September 17, 2014

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

ok can't remember how to do this

- geometry -
**Reiny**, Thursday, January 12, 2012 at 6:31pmA 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 6:33pmYou 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 12:00amIt'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 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 ...

GEOMETRY - PLEASE HELP ME, I HAVE AN EXAM TOMORROW AND THIS THE ONLY QUESTION I ...