Question

Find the total surface area in square kilometers, of the 3-dimensional

Answer 1

Answer: 120 km^2
Explanation:
S = (9x3) + (9x4) + (4x3)2/2 + (9x5)
S= 27 + 36 + 12 + 45
S = 120

Answer 2

 

$\displaystyle\bf\\\textbf{We have a prism with a rectangular triangle base.}\\\\Base~area\!:~~Ab=\frac{3\times4}{2}=\frac{12}{2}=6~km^2\\\\Lateral~area\!:~~Al=(3+4+5)\times9=12\times9=108~km^2\\Total~area\!:~~At=2\times Ab+Al=2\times 6+108=12+108=\boxed{\bf120~km^2}$