What is the Pythagorean theorem?	a^2 + b^2 = c^2, where c is the hypotenuse of a right triangle.
What are the side ratios of a 30-60-90 triangle?	x : x*sqrt(3) : 2x (short leg : long leg : hypotenuse).
What are the side ratios of a 45-45-90 triangle?	x : x : x*sqrt(2) (leg : leg : hypotenuse).
What is the area formula for a triangle?	A = (1/2) * base * height.
What do the interior angles of a triangle sum to?	180 degrees.
What is the sum of interior angles of a polygon with n sides?	(n - 2) * 180 degrees.
What is the area of a circle?	A = pi * r^2.
What is the circumference of a circle?	C = 2 * pi * r (or pi * d).
What is the arc length formula for a central angle of theta degrees?	Arc length = (theta / 360) * 2 * pi * r.
What is the equation of a circle in standard form?	(x - h)^2 + (y - k)^2 = r^2, where (h, k) is the center and r is the radius.
How do you find the midpoint of a segment with endpoints (x1, y1) and (x2, y2)?	Midpoint = ((x1 + x2)/2, (y1 + y2)/2).
What is the distance formula between two points?	d = sqrt((x2 - x1)^2 + (y2 - y1)^2). It's the Pythagorean theorem applied to coordinates.
What is SOH-CAH-TOA?	sin = opposite/hypotenuse, cos = adjacent/hypotenuse, tan = opposite/adjacent.
What is sin(30 degrees)?	1/2.
What is cos(60 degrees)?	1/2. Note: sin(30) = cos(60) because 30 and 60 are complementary angles.
What is the volume of a cylinder?	V = pi * r^2 * h.
What is the volume of a rectangular prism (box)?	V = length * width * height.
What is the relationship between an inscribed angle and its intercepted arc?	An inscribed angle is half the measure of its intercepted arc.