A net of a triangular prism looks like this
1. 13*13*13 =2197
2. 2/5*2/5 = 4/25
3. 0.9*0.9 = 0.81
Finding perimeter is simple. All you do is add up all of the side lengths, and bada bing bada boom, you got the perimeter.
In decimal form it's .75 and that's all you can make it
You need to find "two-fifths of 30." Of here means multiplication:
![\begin{aligned}\dfrac{2}{5}\cdot 30 &= \dfrac{2}{5}\cdot\dfrac{30}{1}\\[0.5em] &= \dfrac{60}{5}\\[0.5em] &= 12\end{aligned}](https://tex.z-dn.net/?f=%5Cbegin%7Baligned%7D%5Cdfrac%7B2%7D%7B5%7D%5Ccdot%2030%20%26%3D%20%5Cdfrac%7B2%7D%7B5%7D%5Ccdot%5Cdfrac%7B30%7D%7B1%7D%5C%5C%5B0.5em%5D%20%26%3D%20%5Cdfrac%7B60%7D%7B5%7D%5C%5C%5B0.5em%5D%20%26%3D%2012%5Cend%7Baligned%7D)
There are 12 athletes in the club.