Question

question 4
which angle is an acute angle?
○ $\angle fbe$
○ $\angle abc$
○ $\angle fba$
○ $\angle fbd$

Explanation:

1. An acute angle is defined as an angle that measures greater than 0° and less than 90°.
2. $\angle FBE$: The right angle symbol shows $\angle FBD = 90°$, so $\angle FBE$ is part of this right angle, making it less than 90° (acute).
3. $\angle ABC$: This is formed by a straight line, so it measures 180° (a straight angle, not acute).
4. $\angle FBA$: This angle is supplementary to the right angle $\angle FBD$, so it measures $180° - 90° = 90°$ (a right angle, not acute).
5. $\angle FBD$: The right angle symbol confirms this is exactly 90° (a right angle, not acute).

Answer:

$\boldsymbol{\angle FBE}$