Question

Find the area of a regular pentagon with a radius of 5m.

I got 43 is that correct?

Answer 1

how did you get 43

Answer 2

wait , lemme rework this real quick, i think i messed up

Answer 3

i reworked it and got 59.3 is that correct?

Answer 4

please wait let me solve mine real quick

Answer 5

ok :)

Answer 6

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&cad=rja&uact=8&ved=0ahUKEwjo1qXnjK3KAhUHxmMKHSB2DXQQtwIIKDAC&url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3D7Gmovmy16YQ&usg=AFQjCNH8XlHd-lgDrfwpseJ1XaG1rT28-A&sig2=_lFnsul94qcoYqyHCn8ztA&bvm=bv.112064104,d.cGc

Answer 7

I think that should help u sorry my calculator is messing up right now

Answer 8

im watching it now :D

Answer 9

yes

Answer 10

It should probably help u

Answer 11

Please tell me if it helped

Answer 12

I get 59.441, not 59.3. Are you evaluating \[\frac{125}{2}\sqrt{\frac{5}{8} + \frac{\sqrt{5}}8}\]

Answer 13

I am doing 1/2 * apothem * perimeter

with values:
1/2 * 29.38 * 4.04 = 59.34 and i have to round the the nearest tenth (according to my directions) and that for me equals 59.3

Answer 14

@whpalmer4

Answer 15

@bookworm14

you are using inaccurate intermediate values, which is distorting the final answer. You truncated \[5\sin(36^\circ)\approx 29.389\]to \(29.38\) instead of rounding it to \(29.39\) and you did the same with the other side. The correct area is \(\approx 59.441032268\), which rounded to the nearest tenth will give a different answer than yours.

Instead of finding the length of one side of the triangle, writing down the first few digits, finding the second side, writing down a few digits, then punching those truncated or even rounded values back in, do the whole calculation in one shot:

\[10*(\frac{!}2*(5\sin(36^\circ)*5\cos(36^\circ))\approx 59.441032268\]