Area of a rectangle
A=bh
Area of a parallelogram
A=bh
Area of a triangle
A=1/2bh
Area of a trapezoid
A=1/2(b1+b2)h
Area of a kite
A=½d₁d₂
Apothem
A perpendicular segment from the center of a regular polygon to a side.
Area of a regular polygon
A=1/2ap or A=1/2asn
Area of a circle
A=πr²
Area of a sector
(arc measure/360)pir^2
Area of a Segment of a Circle
(arc measure/360)pir^2
annulus
the region between two concentric circles
Area of Annulus
πR^2
Surface area of prism
2B+Ph
Surface Area of a Cylinder
2πr² + 2πrh
Surface Area of a Pyramid
B+1/2Ps
Surface Area of a Cone
πrl+πr²
Surface area of a sphere
4πr²