frustum of a cone formula. math's geometric figures on black school board background. mathematical formula

anatomy background brain brainstorm central cerebellum cerebral cerebrum concept creative decisions detail education genius head health human icon idea information intellect intelligence internal isolated left matter medical medicine mind motor nervous neurology occipital organ parietal pink psychology right science selfcontrol sensory sign silhouette spinal cord symbol system think vector white frustum cone formula math's geometric figures black school board mathematical equation formula background