(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Determine the surface area and volume of a solid formed by rotating an equilateral triangle of side a about its base.

2. Relevant equations

3. The attempt at a solution

----------working out surface area--------

Integral of 2.pi.y dx with limits of a and 0.

I worked out; y = root3 . x

therefore surface area = root3.pi.a^2.

------------------------------------------

---------volume of revolution---------------

integral of pi.y^2. dx with limits of a and 0.

y = root3.x

therefore volume of solid formed = pi.a^3

------------------------------------------

I hope someone can check my answer to the first part (working out surface area) and then tell me where i went wrong with the volume of revolution.

The answer for the second part (volume of revolution) should be (pi.a^3)/4

Thanks.

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Solid formed by rotating equilateral triangle.

**Physics Forums | Science Articles, Homework Help, Discussion**