Prealgebra 2e — Original English

Geometric Formulas

2 Dimensions
Name Shape Formulas
Rectangle A rectangular box with the right angle indicated. the length is labeled l and the width is labeled w. Perimeter:P=2l+2wArea:A=lw
Square A square with side length 's' and a right angle indicated in one corner, showcasing a fundamental geometric shape. Perimeter:P=4sArea:A=s2
Triangle A triangle with a dotted line (labeled h) running from the base to the top corner (angle B), creating a 90 degree angle. The legs of the triangle are labeled a, b, and c. The angles of the triangle are labeled B, C, and A. Perimeter:P=a+b+cArea:A=12bhSum of Angles:A+B+C=180°
Right Triangle A right-angled triangle with sides labeled 'a' (vertical), 'b' (horizontal), and 'c' (hypotenuse). A square indicates the right angle at the bottom right corner. Pythagorean Theorem:a2+b2=c2Area:A=12ab
Circle A circle with its center marked 'd'. A dashed line from the center to the circumference indicates the radius 'r'. A horizontal dashed line represents the diameter passing through 'd'. C=2πrCircumference:orC=πdArea:A=πr2
Parellelogram A parallelogram with its base labeled b and its width labeled a. A dotted line (labeled h) runs from the base to the top left corner of the parallelogram, creating a 90 degree angle. Perimeter:P=2a+2bArea:A=bh
Trapezoid A trapezoid with labels a, b, c, and B (for the base). A dotted line (labeled h) runs from the base to the top left corner, creating a 90 degree angle. Perimeter:P=a+b+c+BArea:A=12(B+b)h
3 Dimensions
Name Shape Formulas
Rectangular Solid A 3D rectangular solid with its length, width, and height labeled l, w, and h, respectively. Volume:V=lwhSurface Area:SA=2lw+2wh+2hl
Cube A cube with its height labeled s. Volume:V=s3Surface Area:SA=6s2
Cone An illustration of a right circular cone with its height 'h' and base radius 'r' clearly marked. A dashed line indicates the height from the apex to the center of the circular base, forming a right angle. Volume:V=13πr2hSurface Area:SA=πr2+πrh2+r2
Sphere A diagram of a sphere, displaying its central point and a radius 'r' extending to the edge. A dashed arc indicates the equator, highlighting its three-dimensional structure. Volume:V=43πr3Surface Area:SA=4πr2
Right Circular Cylinder A cylinder with its base radius labeled as r and the height of the cylinder labeled as h. Volume:V=πr2hSurface Area:SA=2πr2+2πrh