Help Ratios Picture added!!

Draw a tape diagram to represent each situation.for some of the situations,you need to decide what to represent with a variable andre bakes 9 pans of brownies.he donates 7 pans to the school bake sale and keeps the rest to divide equally among his class of 30 students

Evaluate cos2θ for cosθ = square root of 3/2

Express the following as a function of a single angle. cos(60) cos(-20) - sin(60) sin(-20)