SHOW WORK PLEASE! 1st find SA, then volume, then the ratio 1. 2cm x 3cm x 4cm 2. 6 cm x 8 cmx 10cm 3. Radius = 4 cm 4 Radius = .75
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Are those cuboids? If so, $\displaystyle Volume_{cuboid} = l\times b \times h$ $\displaystyle Volume_{sphere} = \dfrac43 \pi r^3$ $\displaystyle SA_{cuboid} = 2 lb + 2 lh + 2 lh$ $\displaystyle SA_{sphere} = 4\pi r^2$ Ratio will be simple then.
I know the formulas, it just doesn't work when I do it or is a decimal.
Why not? a) $\displaystyle Volume = lbh = (2)(3)(4) = 24 cm^3$ $\displaystyle SA = 2(2)(3) + 2(3)(4) + 2(2)(4) = 12 + 24 + 16 = 52 cm^2$ Ratio = 24 : 52 = 6 : 13
Thanks, I already got that one. It's just the last two with decimals that I can't solve.
$\displaystyle Volume = \dfrac43 \pi (4)^3 = \dfrac43 \pi (64) = \dfrac{256\pi}{3} cm^3$ $\displaystyle SA = 4 \pi (4)^2 = 64 \pi\ cm^2$ Ratio = 256/3 : 64 = 4 : 3
Thank you, thank you, thank you! But I'm still getting a decimal on the last one D:
Really? =/ $\displaystyle Volume = \dfrac43 \pi (0.75)^3 = \dfrac{9\pi}{16}$ cm^3 $\displaystyle SA = 4\pi (0.75)^2 = \dfrac{9\pi}{4}$ cm^2 Ratio = 9/16 : 9/4 = 4 : 16 = 1 : 4
Yeah, I know, but I missed class on Thursday/Friday so I wasn't exactly taught how to do it. Also, for #2, the ratio 188:225 isn't right, is it?
Oo $\displaystyle Volume = (8)(6)(10) = 480$ cm^3 $\displaystyle SA = 2(8)(6) + 2(8)(10) + 2(6)(10) = 376$ cm^2 Ratio = 480: 376 = 60 : 47
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