Need some major on simplifying non-perfect roots, ?

If sr is 4.5cm and tr is 3cm, what is the measure in degrees of angle s?

Your food costs are $5,500. your total food sales are $11,000. what percent of your food sales do the food costs represent?

Solve this riddle: i am an odd number. i an less than 100. the some of my digit is 12. i am a multiple of 15. what number am i?