KEY GEOMETRY FORMULAS
Remembering these formulas will prove useful for the sizing / brain-teaser questions
asked in an Investment Banking interview, such as:
What is the weight of the Empire State Building?
 Calculating the Volume of the first floor of the ESB
How many tennis balls can you fit into a Boeing 737?
 Calculating the Volume of an aeroplane / tennis ball
If a string wrapped around the equator is made to expand 15 cm, how much more string is
required? (1 metre / 1 km / 10 km)
 Circumference of a circle
Abbreviations
𝑟 = Radius 𝑙 = Length 𝑤 = Width ℎ = Height 𝑏 = Base
2-D Shapes
3-D Shapes
Circle:
Area = 𝜋𝑟 2
Circumference = 2𝜋𝑟
Rectangular Prism:
Surface Area = 2ሺ𝑙 × 𝑤ሻ + 2ሺℎ × 𝑤ሻ + 2ሺℎ × 𝑙ሻ
Volume = ℎ × 𝑙 × 𝑤
Rectangle:
Area = 𝑙 × 𝑤
Cylinder:
Surface Area = 2𝜋𝑟ℎ
Volume = 𝜋𝑟 2 ℎ
Triangle:
1
Area = 2 𝑏ℎ
Trapezoid:
1
Area = ሺ𝑏1 + 𝑏2ሻℎ
2
Sphere:
Surface Area = 4𝜋𝑟 2
4
Volume = 3 𝜋𝑟 3
Cone:
Surface Area = 𝜋𝑟ሺ𝑟 + ξ𝑟 2 + ℎ2 ሻ
1
Volume = 3 𝜋𝑟 2 ℎ