Find the total surface area of this prism where the cross-section is an isosceles triangle

The axis of symmetry for the graph of the function f(x)=1/4^2+bx +10 is x=6. what is the value of b?

What is the volume of the sphere shown below with a radius of 3?

Set $r$ is a set of rectangles such that (1) only the grid points shown here are used as vertices, (2) all sides are vertical or horizontal and (3) no two rectangles in the set are congruent. if $r$ contains the maximum possible number of rectangles given these conditions, what fraction of the rectangles in set $r$ are squares? express your answer as a common fraction.