Question

Difficulty: MediumLines and Angles

An aviation engineer is evaluating the intersection of two flight paths on a radar display. The flight paths are represented by two straight intersecting lines. Two adjacent angles formed by this intersection have measures of (8x)∘(8x)^\circ and (2x+10)∘(2x + 10)^\circ. What is the measure of the smaller of these two adjacent angles?

  1. A
    26∘26^\circ
  2. B
    28∘28^\circ
  3. C
    34∘34^\circ
  4. 44∘44^\circAnswer

Answer

The smaller angle measures 44∘44^\circ.
Adjacent angles on a straight line form a linear pair and are supplementary, meaning their sum is 180 degrees. Setting up the equation 8x + 2x + 10 = 180 simplifies to 10x + 10 = 180. Subtracting 10 from both sides leaves 10x = 170, and dividing by 10 yields x = 17. Substituting x back into the expressions gives angle measures of 8(17) = 136 degrees and 2(17) + 10 = 44 degrees. The question asks for the smaller angle, which is 44 degrees.

Step-by-Step Solution

1
Recognize that adjacent angles formed by intersecting lines create a linear pair.
The angles are supplementary, meaning their sum is 180∘180^\circ.
This geometric rule provides the basis for setting up the equation.
2
Set up an equation representing the sum of the two angles.
8x+(2x+10)=1808x + (2x + 10) = 180
This translates the geometric relationship into an algebraic expression.
3
Combine the like terms on the left side of the equation.
10x+10=18010x + 10 = 180
Simplifying the equation is the first step in isolating the variable x.
4
Solve for x by subtracting 10 from both sides and then dividing by 10.
10x=170⇒x=1710x = 170 \Rightarrow x = 17
These standard algebraic operations isolate x and determine its exact value.
5
Substitute x = 17 back into both original expressions to find the angle measures.
8(17)=136∘8(17) = 136^\circ and 2(17)+10=34+10=44∘2(17) + 10 = 34 + 10 = 44^\circ
The question asks for a specific angle measure, not the variable x.
6
Identify the smaller of the two calculated angles.
44∘44^\circ
The prompt specifically requests the measure of the smaller angle.

Key Concept

Linear pairs of angles form a straight line and are supplementary, meaning they add up to 180 degrees.
Estimated Time:1m 15s
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