Geometry

Question Analysis

This question focuses on identifying the measurement of an obtuse angle from a set of given options. The main task is understanding the definition of an obtuse angle and distinguishing it from other angle types.

 

Key Concept Explanation

 An obtuse angle is defined as an angle that measures greater than 90° but less than 180°. In contrast, acute angles measure less than 90°, right angles measure exactly 90°, and straight angles measure 180°.

 

Step - by - Step Solution

1. Examine each option one by one and compare it to the range for obtuse angles (greater than 90° and less than 180°).

2. Determine which option falls within this specific range.

 

Option Analysis

60°: Since 60° is less than 90°, it is an acute angle, not an obtuse angle.

90°: This is the measurement of a right angle, not an obtuse angle.

145°: As 90° < 145° < 180°, it is within the range for obtuse angles, so this is the correct answer.

180°: This is the measurement of a straig...