Question

Area = 1/2 ap. I need to find the area of a 3-gon with 6 inch side! Please help!

Answer 1

I'm assuming that this is a regular triangle?

Answer 2

Equilateral triangle

Answer 3

Alright. This will only work for equilateral triangles. Normally you have to find the apothem using trigonometry, but for equilateral triangles, you can just use the formula:
\[A = \frac14s^{2}√3\]

Answer 4

Is that the same for geometry or is that for trigonometry.

Answer 5

? I'm not sure what you mean. THis is a formula you can always use for equilateral triangles no matter what level of math you're in. You just have to take the effort to memorize it. Just plug in 6 for s. Again, this formula only works for equilateral triangles.

Answer 6

You can also derive the formula; you don't need to memorise it.

Answer 7

\[A=\frac 12 \times \text{opp} \times s=\frac 12\times\frac{\sqrt 3}{2}s\times s=\frac{\sqrt 3}{4}s^2\]