What two quantities must be known when finding the volume of a solid?

Area and height

Step-by-step explanation:

Required

What must be known to calculate volume

To calculate volume, you need:

This is proved by the formula below:

The volume of a solid is:

i.e. the product of the area of the solid and the height of the solid.

So, from the formula above: the height and the area must be known

check the picture below.

well, the angle at the vertex d is clearly not a right-angle, let's check for the one at the vertex f which does look like,   however if it's indeed, that means ef is perpendicular to df, in which case their slopes will be negative reciprocal of each other.

so the negative reciprocal of the slope of ef is 1, however the slope of df is not 1, is 1/2, so nope, they're not perpendicular lines.

so then what are you asking?

step-by-step explanation: