Aregular polygon must have sides if each interior angle measure is four times the measure of each exterior angle

If tan2a=cot(a+60), find the value of a, where 2a is an acute angle

Find the equation of the ellipse with the following properties. the ellipse with foci at (0, 6) and (0, -6); y-intercepts (0, 8) and (0, -8).edit: the answer is x^2 over 28 + y^2 over 64 = 1

Simplify. 3(4+4x) (type your answer in with no spaces)