Just need an equation telling me how to solve surface area for the iscosahedron. PLZ SOMEONE HELP!
2007-01-19 14:08:36 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
1) find the area of 1 triangle.
A=.75s^2 tan 30°
A=.75s^2*√3 /3
A=.25√3 * s^2
2) multiply by 20
5√3 *s^2
2007-01-19 14:18:49 · answer #1 · answered by yupchagee 7 · 9⤊ 0⤋
Formula for Area of a Triangle is
A= 1/2abSinC
In your case a=b so A= (1/2)*a^2*Sin60
Equilateral triangles have 60 degree angles
Sin60 = Sqrt(3) /2
A= (a^2)(Sqrt(3) /4)
Now just multiply by 20 since you have 20 of these triangles.
2007-01-27 09:22:26 · answer #2 · answered by J B 2 · 0⤊ 0⤋
An icosahedron has 20 identical sides that are all equilateral triangles. If you know the length of an edge then you can calculate the area of one face. Just multiply that by 20.
2007-01-19 14:16:29 · answer #3 · answered by Northstar 7 · 0⤊ 0⤋