Isosceles and Equilateral triangles question! 60 POINTS!! How do I figure out what "a" is equal to? Thanks!

Write 17/20 as a decimal and as a percent.

Average acceleration: i have no idea how to do this.

Find the measure of angle y. round your answer to the nearest hundredth. ( type the numerical answer only) a right triangle is shown with one leg measuring 5 and another leg measuring 14. an angle across from the leg measuring 5 is marked y degrees. numerical answers expected!