PLEASE EXPLAIN AND SHOW STEPS:

Write a function for a rotation 90 degrees counter clockwise about the origin, point 0

1) what is the measure of the exterior angle, ∠uvw ? 2) in triangle man, what is the measure of the exterior angle at n (in degrees)?

Atorch and a battery cost 2.50 altogether.the torch costs 1.50 more than the battery.what fraction of the total price is the torch? give your answer in its simplest form.