Geometry

Question Analysis:

This question involves using the concept of adjacent angles to find the measure of an angle.

 

Key Concept Explanation:

The angle - addition postulate states that if two adjacent angles share a common vertex and a common side, the measure of the larger angle formed by them is the sum of the measures of the two smaller adjacent angles.

 

Step - by - Step Solution:

1. Observe the figure and identify the adjacent angles that make up ∠HFE. Here, ∠HFE is composed of ∠EFG and ∠GFH.

2. Note the measures of the adjacent angles: m∠EFG = 15° and m∠GFH = 39°.

3. Apply the angle - addition postulate: m∠HFE=m∠EFG + m∠GFH.

4. Substitute the values: m∠HFE = 15°+39° = 54°.

 

Common Mistakes:

Forgetting to use ...