Learn the variables of geometry. The set of variables remain as constants in the sphere of geometry. These variables are: V, b, h, l, r, w, and π. V stands for volume, the area within a closed shape that is encompassed within the shape's perimeter the equations are solving for. B is for base, the area of a flat-bottomed shape. H is height, how tall an object is above the plane on which it is resting. L is length. R stands for radius, the distance from the center or a circle to the edge in a straight line. W is width. Pi is 22/7 or 3.14, a standard accepted truncation of the ratio.
Recognize the shapes in standard elementary geometry. There are seven shapes of which the volume can be found. A cone is a three-dimensional geometric shape that tapers from a flat, circular base to the centralized apex. Spheres are perfectly round geometric shapes, like a globe or ball. A pyramid comes from a polygonal shape to an apex, like a cone. A cube is a box, a regular hexahedron with six square facets. A cuboid is also a six-faceted three-dimensional object (a box), however instead of square, each side is merely required to be a quadrilateral. A quadrilateral is a four-sided shape made of two sets of parallel sides. Cylinders are tubes, a circular base that continues to be circular, like circles stacked on top of one another. A prism, like a cylinder, is a a three-dimensional stack with a regular shaped base. Prisms are named for the shape of the base, so a prism with a six-sided bottom would be a hexagonal prism.
Memorize the equations used to solve for volume.
Volume of a cone: V=Bh/3
Volume of a sphere: V = 4πr³/3
Volume of a pyramid: V= Bh/3
Volume of a cube: V=l³
Volume of a cuboid V=lhw
Volume of a cylinder: V = Bh
Volume of a prism: V = Bh