Question

Find the volume of the square pyramid shown. Round to the nearest tenth if necessary.
(Picture one)

A. 126 cm3
B. 907.5 cm3
C. 605 cm3
D. 55 cm3

Find the surface area of the cylinder in terms of pi.
(Picture 2)

A) 396 pi in^2
B) 522 pi in^2
C) 360 pi in^2
D) 1008 pi in^2

Answer 1

$\bf \textit{volume of a pyramid}\\\\ V=\cfrac{1}{3}Bh\qquad \begin{cases} B=\textit{area of the base}\\ h=height\\ ----------\\ B=11\cdot 11\\ \qquad 121\\ h=15 \end{cases}\implies V=\cfrac{1}{3}(121)(15)\\\\ -------------------------------\\\\ \textit{surface area of a cylinder}\\\\ s = 2\pi r(h+r)\qquad \begin{cases} r=radius\\ h=height\\ -----\\ r=9\\ h=20 \end{cases}\implies s=2\pi(9)(20+9)$