Locate the complete gerund or infinitive phrase and identify its use. her motive was to keep peace in the family.

The infinitive is to keep peace in the family and it functions as a predicate noun

Explanation:

An infinitive is a verb that is used in its base form after the preposition "to" (eg. to run, to play, to eat) infinitives have several functions and uses, this sentence has an infinitive for purpose, and in the syntaxis, it covers the function of a predicate noun which always follows a verb and makes reference to the subject of the sentence

Acute angle

Step-by-step explanation:

The supplement of an obtuse angle is an acute angle