Sunday, February 3, 2008

Pentagons

In case you need some help getting the angles right, see this.

I misspoke in class earlier this week when I said the outer angles are 72 degrees. The inside angles when drawing lines from the center to each vertex are 72 degrees, the outer angles are 108 degrees.

2 comments:

Anonymous said...

so does that mean that everything should stay the same except for we should use (1-cos108) instead of (1-cos72)?

pleclair said...

for number 9, yes, use 108 degrees everywhere instead.

for number 10, the length from a vertex to the center does use the 72 degree angle, so nothing changes on that one.