--[=[
	Solving for angle across from c

	@param a number
	@param b number
	@param c number
	@return number? -- Returns nil if this cannot be solved for
]=]

function Math.lawOfCosines(a: number, b: number, c: number): number?
	local l = (a*a + b*b - c*c) / (2 * a * b)
	local angle = math.acos(l)
	if angle ~= angle then
		return nil
	end
	return angle
end
