Geometry

Question Analysis

This question focuses on measuring an angle using a protractor without a direct 0 - degree starting point. The main task is accurately reading the protractor's scale to determine the angle's measurement.

 

Key Concept Explanation

A protractor has two scales (inner and outer), each ranging from 0° to 180°. When both sides of the angle intersect the protractor away from 0°, we measure the angle by calculating the difference between the scale values on the same scale at the intersection points of the two sides with the protractor.

 

Step - by - Step Solution

1. Determine the scale:

Observe that the initial side of the angle is closer to the right - hand side  of the protractor, so we use the inner - ring scale.

The inner - ring scale reading of the initial side is approximately .

The inner - ring scale reading of the terminal side is approximately .

 

2. Calculate the angle:

Subtract the initial side reading from the terminal side reading. So the angle measurement is

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