Question

select the acute angle.

Explanation:

Step1: Recall angle - type definitions

An acute angle is an angle whose measure is between 0° and 90°.

Step2: Analyze each option

The first angle (top - most) is clearly between 0° and 90°. The second angle is an obtuse angle (greater than 90° and less than 180°). The third angle is a straight angle (equal to 180°). The fourth option (image) does not clearly represent an angle for the purpose of this question.

Answer:

The first angle (top - most) shown in the question is the acute angle.