Please help (this is 12 year old math)​

In a right triangle δabc, the length of leg ac = 5 ft and the hypotenuse ab = 13 ft. find: b the length of the angle bisector of angle ∠a.

Parabolas y=−2x^2 and y=2x^2+k intersect at points a and b that are in the third and the fourth quadrants respectively. find k if length of the segment ab is 5.

An equation in slope-intersept form the lines that passes thought (-8,1) and is perpindicular to the y=2x-17.