5.3 Angle Bisectors in Triangles

Question 4:

Angle [tex]\( \text{ABC} \)[/tex] is bisected by line segment [tex]\( \text{AD} \)[/tex]. If angle [tex]\( \text{ABC} \)[/tex] measures [tex]\( 50^\circ \)[/tex] and one of the smaller angles created by [tex]\( \text{AD} \)[/tex] measures [tex]\( (2x + 1)^\circ \)[/tex], what is the value of [tex]\( x \)[/tex]?

A. 25

B. 24

C. 12

D. 18



Answer :

Let's solve this geometry problem step-by-step.

1. Understand the Problem:
- Angle [tex]\( ABC \)[/tex] measures [tex]\( 50^\circ \)[/tex].
- Line segment [tex]\( AD \)[/tex] bisects [tex]\( \angle ABC \)[/tex], meaning it divides [tex]\( \angle ABC \)[/tex] into two equal smaller angles.
- One of these smaller angles is represented as [tex]\( 2x + 1 \)[/tex] degrees.
- We need to determine the value of [tex]\( x \)[/tex].

2. Determine the Measure of the Smaller Angles:
Since [tex]\( AD \)[/tex] bisects [tex]\( \angle ABC \)[/tex], each smaller angle will be half of [tex]\( \angle ABC \)[/tex]:
[tex]\[ \text{Measure of each smaller angle} = \frac{\angle ABC}{2} = \frac{50^\circ}{2} = 25^\circ \][/tex]

3. Set Up the Equation:
Given that one of these smaller angles is represented by [tex]\( 2x + 1 \)[/tex] degrees, we can set up the following equation:
[tex]\[ 2x + 1 = 25 \][/tex]

4. Solve for [tex]\( x \)[/tex]:
- Subtract 1 from both sides of the equation:
[tex]\[ 2x = 25 - 1 \][/tex]
[tex]\[ 2x = 24 \][/tex]
- Divide both sides by 2:
[tex]\[ x = \frac{24}{2} \][/tex]
[tex]\[ x = 12 \][/tex]

5. Conclusion:
The value of [tex]\( x \)[/tex] is [tex]\( \boxed{12} \)[/tex].

By following the steps and solving the equation, we determined that the value of [tex]\( x \)[/tex] is [tex]\( 12 \)[/tex].