The side lengths of a triangle projected on a cloud are 16 feet, 16 feet, and 20 feet. the longest side of the triangle on the spotlight is 0.5 feet long. what is the perimeter of the triangle on the spotlight?

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?