Afishing boat using sonar to locate fish is employing
diffraction
reflection
refraction
interference

reflection

Explanation:

SONAR - Sound Navigation and Ranging

It works on the principle of Echo i.e. the reflection of sound. Sound waves are sent out which get bounced off a nearby object. The reflected sound waves is detected and distance to the object is estimated. Sonar is used to detect, navigate or communicate  objects underwater. Thus, a fishing boat uses sonar to locate the fish. It is employing reflection.

i dont think you are wrong for wanting to get even with someone who did you wrong.

(i'm an eye for an eye kind of person) but if this person hurt you in a sexual way, i dont suggest doing anything to him. he should be taken to the proper authorities, you could go to jail depending on what you do. if it was something small like your sibling took your spot on the couch, than yea, i would get even with him by taking one of his favorite snacks lol. but i dont suggest you doing anything illegal.

the area between the graph and the t axis