A partial cylinder lies on its side. The bases are a 90° sector of a circle. What is the exact volume of the partial cylinder?

Question

anonymous · Answer

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I substituted in a value for the radius of a circle, and used the fact that 90 degree sector is 1/4 of a total circle to determine what the area of the sector was. 

Using that information, I could use my made-up number to accurately determine the whole volume of the special cylinder. But I can't! I don't know the height of this shape, and only the area of its base. So this problem...Is unsolvable. I'm sorry.

anonymous · Answer

Thank you for trying to help :D

anonymous · Answer

Ha-ha! Absolutely. Do we know the height of the cylinder? If we do, then we can finish what we started.

anonymous · Answer

r = 8in. w= 10 in.

anonymous · Answer

What does 'w' stand for?

anonymous · Answer

lol i got it... but i need help one another one

anonymous · Answer

I'd be glad to help in just a moment, if you want.

anonymous · Answer

A square pyramid has sides of 8 m. Each face is an equilateral triangle.

What is the lateral area of the pyramid?

anonymous · Answer

attachment

anonymous · Answer

here are the answers 128 m2
128 m2
32 m2
64 m2

anonymous · Answer

Alrighty...

anonymous · Answer

You can determine the area of these triangles by finding the height of one of them. You do this by splitting the triangle in half: 

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And using the Pythagorean theorem to solve. I'm sure you see how.

Once you find the height, use the formula for finding the area of the triangle. Multiply this area by four, since there are four triangles in this figure. Add that result to the area of the base square, and you're finished!