Answer:
The angle between his home, his friends house and grocery store
Explanation:
The given angle are;
The angle between the bus stop, the park and his home
The Angle Angle Similarity Theorem can be used to determine if the streets are parallel by verifying if there are congruent corresponding angles on the streets between his friends house and the grocery store and the street between the park and the bus stop
Therefore, the angle he needs to know is the angle between his home, his friends house and grocery store which are same side interior angles and they should sum to 180° to give the angle between the road and the other side of his friend's house