Geometry Flashcards
Sum of angles
180°
Area
½ah
(h is height)
Pythagorean Therorem
Right triangle with sides a, b and hypotenuse c
c2 = a2 + b2
Area
Right triangle with sides a, b and hypotenuse c
½ab
Perimeter
Rectangle with sides a, b
2(a + b)
Area
Rectangle with sides a, b
ab
perimeter
Square with sides a
4a
Area
Square with sides a
a2
Diagonal
Square with sides a
a√2
Diameter
Circle of radius r
2r
Circumference
Circle of radius r
2𝜋r
Area
Circle of radius r
𝜋r2
Arc length
Sector of a circle of radius r and angle 𝜃 (in radians):
r𝜃
Area of sector
Sector of a circle of radius r and angle 𝜃 (in radians):
r2𝜃/2
Area
Ellipse with semi-axes a and b
𝜋ab
Area
Trapezoid with sides a, b, c, d and height h. Sides a and b are parallel
½(a + b)h
Volume
Parallelepiped of length a, width b, and height c:
V = abc
Surface area
Parallelepiped of length a, width b, and height c:
Surface area = 2(ab + ac + bc)
Volume
Cube of side a
a3
Surface area
Cube of side a
6a2
Volume
Sphere of radius r
4/3𝜋r3
Surface area
Sphere of radius r
4𝜋r2
Volume
Ellipsoid with semi-axes a, b and c
4/3𝜋abc*
Volume
Cylinder of radius r and height h
𝜋r2h
Lateral surface area
Cylinder of radius r and height h
2𝜋rh
Volume
Cone of radius r and height h
⅓𝜋r2h
Volume
Pyramid of height h whose base is a rectangle with sides a, b
⅓abh
