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:
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 
\(\Sigma \theta = (n2) \cdot 180^\circ\)  \(\Sigma \theta\) = 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 
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