25. The screen of Angelo's eBook reader has a width of 12 centimeters and an area of 228 square centimeters. What is the length of the
screen in centimeters? (CC.6.RP.3d)
19 centimeters
(A
B)
216 centimeters
© 240 centimeters
D 2,736 centimeters

Ihonestly don’t understand this at all

When you answer this can you explain

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?