Question

Someone help me with my math homework pleaseee. Find the volumes of the pyramids and the height is 7cm for the first one.

Answer 1

$\bf \textit{volume of a pyramid}\\\\ V=\cfrac{1}{3}Bh\qquad \begin{cases} B=\textit{area of the base}\\ h=height \end{cases}$

now, the first one, on the far-left.... can't see the height.. but I gather you do, now as far as its Base area, well, the bottom is just a 12x12 square, so the area of its base is just 12*12


now, the middle pyramid, has a height of 6, the base is also a square, 8x8, so the Base area is just 8*8

now the last one on the far-right

has a height of 8, the Base is a Hexagon, with sides of 6

$\bf \textit{area of a regular polygon}\\\\ A=\cfrac{1}{4}ns^2cot\left( \frac{180}{n} \right)\qquad \begin{cases} n=\textit{number of sides}\\ s=\textit{length of one side}\\ \frac{180}{n}=\textit{angle in degrees}\\ ----------\\ n=6\\ s=6 \end{cases}\\\\\\ A=\cfrac{1}{4}\cdot 6\cdot 6^2\cdot cot\left( \frac{180}{6} \right)$