May 4th, 2003, 09:32 PM
Areas of Regular Polygons
I need help with a math problem (yes its for school i dont need the answer just some direction as my book doesnt explain some stuff very well)
Ok, i need to find the area of a regular pentagon with perimeter 60 and apothem X.
Area = 1/2 apothem*perimeter
first you need to make a right triangle out of this. Area of regular polygons has to be done as if circumscribed in a circle.
Mathgirl32 i need you ! :P
May 5th, 2003, 11:51 PM
Um, I don't really know or remember what an apothem is. If you can tell me than I can probably help you. By the way I searched on Google for what an Apothem was. I haven't found a source that told me what one was for a pentagon but I did come across a site that might help you. Here is a link to their FAQ. Thats all I can do for now.
May 11th, 2003, 10:53 AM
I hate geometry, especially trig. I didn't feel like figuring this one out on my own (it's 5:00 AM) so here.
This should explain everything you need to know. If you have anymore questions, ask. I'll answer them in the morning. Zzz....
\"If you can\'t make it good, make it look good.\" - Bill Gates
May 14th, 2003, 02:47 PM
yeah, I\'m gonna need that by friday...
May 14th, 2003, 04:28 PM
The way I remember it is that every regular polygon can be split into a number of triangles equal to the number of sides in the polygon (in this case, 5). Since you know the length of one of the sides (60/5 = 12) and the angle between each side (540 angles in a pentagon, divided by 5 is 108).
To calculate the angles in a regular polygon, just take the number of sides, subtract two and multiply your answer by 180 (working in degrees here, not radians).
Hope this helps.