The volume of a regular triangular prism is 90 sqrt of 3 cm^3. If the radius of the inscribed circle in the base is 3 cm, find the altitude of the prism.
could you help me to solve that?

Question

The volume of a regular triangular prism is 90 sqrt of 3 cm^3. If the radius of the inscribed circle in the base is 3 cm, find the altitude of the prism.
could you help me to solve that?

anonymous · Answer

no. the answer should be 3.3333..

akashdeepdeb · Answer

I am sorry you said TRIANGLUR???? :D
hold on then..... :D

anonymous · Answer

haha its ok :)

akashdeepdeb · Answer

|dw:1377029078330:dw|

akashdeepdeb · Answer

base area = rt 3 * (side)^2/4
rt 3 * 3 = |dw:1377029278359:dw|

akashdeepdeb · Answer

THIS IS THE UPDATED AND CORRECTED IMAGE!!

akashdeepdeb · Answer

so base area = area of equilateral triangle!! :D
rt 3 * (side)^2/4
rt 3 * 27 = 27 rt 3
So altitude = volume/base area = 90 rt 3/27 rt 3 = 90/27 = 3.333333333333333333333333333333333333333333333333 cm :D
Understood the question?

anonymous · Answer

im sorry ha. what is rt by the way?

akashdeepdeb · Answer

Under root or square root

anonymous · Answer

i got it. thank you!

akashdeepdeb · Answer

:)

anonymous · Answer

i have another problem

anonymous · Answer

A metal hallow bar whose cross-section and dimensions are shown below weighs 8*10^3 kg/m^3 and measures 2m in length. determine the mass of the metal bar with a square hole section.