Any two numbers you multiply together that are both even will always result in an even number. For example 48x24=1152. You can use any two even numbers and you will always get and even product.
The base of a cone is something circular, like a circle or an ellipse. The rest of the options (square, triangle, and pentagon) are all based of pyramids, not cones. Cones have to have a circular base because otherwise they'd be pyramids.
