130bcd
Posts:
1
Registered:
5/28/13


Trying to find perimeter of a regular pentagon
Posted:
May 28, 2013 11:15 AM


Hello,
I have unsuccessfully tried to find the perimeter of a pentagon. The "radius" to the vertices is 130, which I tried to convert into 5 triangles but I can't find a formula for determining the length of the 3rd side of an isosceles triangle.
The two equal length sides would, of course be 130 and the angle between them would be 72.
Help, please!

