How do i solve and simplify this if needed?

If a =6, what is the value of 2a(3b + 5c)?

Points a, b, and c form a triangle. complete the statements to prove that the sum of the interior angles of triangle abc is 180

Apyramid fits exactly inside a cube. the cube and the pyramid share the same square base, and they are both exactly the same height. the volume of the cube is 66 cubic inches. what is the volume of the pyramid? explain your answer. answer asap