Amissing fraction on a number line is located exactly halfway between 3/6 and 5/6. what is the missing fraction

The perimeter of a triangle is 69 cm. the first is 5 cm shorter than the second side. the third side is twice as long the first side. find the length of each side

The base of a triangle exceeds the height by 9 inches. if the area is 180 square inches, find the length of the base and the height of the triangle.

If cos(2x) = tan^2(y), show that cos(2y) = tan^2(x).