Important Geometry Formulas to Know for the ISEE Math Tests

Geometry! Greeks loved it, but most people not so much. However, geometry is everywhere, and furthermore, you need to know geometry as one of the 4 important areas of math if you want to ace the Mathematics Achievement and Quantitative Reasoning tests on the ISEE. Geometry tends to be confusing due to the huge number of formulas and concepts, but at Union Test Prep, we’ve narrowed it down to the essential formulas so you can have them all in a single chart.

Use the chart below and our other three formula charts (linked below) as you prepare for the ISEE test:

• Formulas for Numbers and Operations on the ISEE Test

• Formulas for Algebra on the ISEE Test

• Formulas for Data Analysis, Probability, and Statistics on the ISEE Test

For practice and more information, check out our FREE study guides, practice questions, and flashcards for the ISEE.

Geometry Formulas for the ISEE Math Tests

Category	Formula	Symbols	Comment
Two Dimensional Shapes	\(\Sigma \theta = (n-2) \cdot 180^\circ\)	\(\Sigma \theta\) = sum of interior angles n = number of sides of a polygon
Two Dimensional Shapes	\(P=s_1 + s_2 + s_3\)	P = Perimeter of a triangle \(s_n\) = side length
Two Dimensional Shapes	\(A=\frac{1}{2} \cdot b \cdot h\)	A = area of triangle b = base h = height
Two Dimensional Shapes	\(a^2+b^2=c^2\)	a, b = legs of a right triangle c = hypotenuse of a right triangle
Two Dimensional Shapes	\(P=4 \cdot s\)	P = Perimeter of a square s = side length
Two Dimensional Shapes	\(P=(2 \cdot l)+(2 \cdot w)\)	P = Perimeter of a rectangle l = length w = width
Two Dimensional Shapes	\(A=s^2\)	A = Area of a square s = side length
Two Dimensional Shapes	\(A=l \cdot w\)	A = Area of a rectangle l = length w = width
Two Dimensional Shapes	\(A=h \cdot \frac{(b_1+b_2)}{2}\)	A = Area of a trapezoid \(b_n\) = base n h = height
Two Dimensional Shapes	\(C=2 \cdot \pi \cdot r\) or \(C=\pi \cdot d\)	C = Perimeter of a circle r = radius d = diameter
Two Dimensional Shapes	\(S=r \theta\)	s = arc length r = radius \(\theta\) = central angle (radians)
Two Dimensional Shapes	\(A=\pi \cdot r^2\)	A = Area of a circle r = radius
Three Dimensional Shapes	\(V=l \cdot w \cdot h\)	V = Volume of a rectangular prism l = length w = width h = height
Three Dimensional Shapes	\(SA= \Sigma A_{fi}\)	SA = Surface Area of a prism \(A_{fi}\) = Area of face i
Three Dimensional Shapes	\(V=\frac{1}{3} \cdot (l \cdot w \cdot h)\)	V = Volume of a pyramid with rectangular base l = length w = width h = height
Three Dimensional Shapes	\(SA=\Sigma A_{fi}\)	SA = Surface Area of a pyramid \(A_{fi}\) = Area of face i
Three Dimensional Shapes	\(V= \pi \cdot r^2 \cdot h\)	V = Volume of a cylinder r = radius h = height
Three Dimensional Shapes	\(SA=2B+(C \cdot h)\)	SA = Surface Area of a cylinder B = Area of the Base C = Circumference of the Base h = height
Three Dimensional Shapes	\(V= \frac{4}{3} \cdot \pi \cdot r^3\)	V = Volume of a sphere r = radius
Three Dimensional Shapes	\(SA=4 \cdot \pi \cdot r^2\)	SA = Surface Area of a sphere r = radius of the sphere