Question

Please help use 3 for PI and i dont know if theirs a decimal or not

Answer 1

192

Explanation:

The formula for the volume of a cone is given in the problem as:

`V=(\pi r^2h)/(3)`

The problem instructs us to use "3" as the value for π. (In this case, it might be helpful to think of π as a letter like "y", and we're just substituting in the value that they give us... π=3).

At the bottom of the cone, the full diameter of the circular base is given as 8 cm. The radius (the "r" in the formula) of a circle, is half of the diameter:

r = 1/2 * d

r = 1/2 * (8cm)

r = 4cm

We're also given the height ("h" in the formula) in the diagram as 12 cm. It is the height because it is the measurement of the distance from the vertex (top) to the base where the line segment measured forms a right angle (as indicated by the "square" where that line segment meets the base).

Substituting the known values into the formula, we get...

`V=((3) (4cm)^2 (12cm))/(3)`

Simplifying/evaluating the expression, we follow order of operations (exponents, then multiplication/division)...

`V=((3) (16cm^2) (12cm))/(3)`

`V=(576cm^3)/(3)`

`V=192cm^3`

Answer 2

3.133333333333

hope this helps :)