What's the HIGHEST level of infinity? Please answer

Write the sine and cosine values of a, b, respectively, in the figure for (1) and (2) + explanation.

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?

What is the distance between a and b? round your answer to the nearest tenth. a coordinate plane is shown. point a is located at negative 1, 5, and point b is located at 4, 1. a line segment connects the two points.