Question

a weathervane is pointing north. after the wind changes direction, the weathervane points east. the turn forms a right angle. how many degrees did the arrow turn?

Explanation:

Step1: Recall right angle measure

A right angle is defined as an angle of $90^\circ$.

Step2: Analyze weathervane turn

The weathervane turns from North to East, and the angle between North and East (a right angle) is $90^\circ$. So the arrow turned by the measure of a right angle.

Answer:

$90$ degrees