Question

click on the obtuse angle.

Explanation:

Step1: Recall definitions

An acute angle is less than \(90^{\circ}\), a right - angle is equal to \(90^{\circ}\), an obtuse angle is between \(90^{\circ}\) and \(180^{\circ}\), and a straight angle is equal to \(180^{\circ}\).

Step2: Analyze each angle

• The first angle: It is between \(90^{\circ}\) and \(180^{\circ}\), so it is an obtuse angle.
• The second angle: It is less than \(90^{\circ}\), so it is an acute angle.
• The third angle: It has a right - angle symbol (\(90^{\circ}\)), so it is a right - angle.
• The fourth angle: It is a straight line (\(180^{\circ}\)), so it is a straight angle.

Answer:

The first angle (the one that is between \(90^{\circ}\) and \(180^{\circ}\)) is the obtuse angle.