# Mathematical Equations

 To find the circumference of a circle, multiply the diameter by 3.1416 To find the diameter of a circle, multiply the circumference by .31831. To find the area of a circle, multiply the square of the diameter by .7854. To find the area of a rectangle, multiply the length by the width. To find the area of a triangle, multiply the base by 1/2 the perpendicular height. To find the area of an ellipse, multiply the product of both diameters by .7854 To find the area of a parallelogram, multiply the base by the altitude. To find the side of an inscribed square, multiply the diameter by .7071 or multiply the circumference by .2251 or divide the circumference by 4.4428. To find the side of an inscribed cube, multiply the radius of the sphere by 1.1547 To find the side of a square of equal area of a circle, multiply the diameter by .8862 To find the surface of a sphere, square the diameter and multiply by 3.1416 To find the volume of a sphere, cube the diameter and multiply by .5236. A side of a square multiplied by 1.4142 equals the diameter of it’s circumscribing circle. The side of a square multiplied by 1.128 equals the diameter of a circle of equal area. To find the gallon capacity of a tank (given the dimensions of the cylinder in inches), square the diameter of the cylinder the multiply by the length and by .0034