An image of a rectangular pyramid is shown below:

a right rectangular pyramid is shown.

part a: a cross section of the rectangular pyramid is cut with a plane parallel to the base. what is the name of the shape created by the cross section? explain your answer.

part b: if a cross section of the rectangular pyramid is cut perpendicular to the base, passing through the top vertex, what would be the shape of the resulting cross section? explain your answer.

Each person in an it department of 25 people works on at least one of 3 major projects: system security, program implementation, platform development. 10 people work on system security, 13 work on program implementation, and 12 work on platform development. 4 people work on system security and platform development, 5 people work on program implementation and platform development, and 2 people work on all three projects. how many people work on system security and program implementation?