The height of a cylinder is twice the radius of its base. What expression represents the volume of the cylinder, in

cubic units?

4pix2

2pix3

pix2+2x

2+pix3

The answer is 2pix3 or  

Step-by-step explanation:

This problem brothers on the mensuration of solid shapes, a cylinder.

we know that the expression for the volume of a cylinder is

let the radius r of the base be=  x

and the height h of the cylinder be =  2x

we can now solve the expression that represents the volume of the cylinder, in cubic  units.

because linear equations are a lot simpler than quadratics equations, and linear equations formula is a lot easier to memorize. that's why i think they're harder.

the surface area is 124cm²

step-by-step explanation:

length: 4cm

width: 9cm

height:   2cm