Question 10·Easy·Lines, Angles, and Triangles
Two hiking trails intersect at point , forming four angles. One of the angles measures . The angle adjacent to this angle that forms a straight line with it is labeled . What is the value of ?
When a problem says two adjacent angles form a straight line, immediately use the supplementary relationship: their measures add to . Set up and subtract.
Hints
Identify the relationship
An angle and its adjacent angle that make a straight line always add to .
Set up an equation
Write an equation using .
Compute the missing angle
Subtract from to find .
Desmos Guide
Enter the subtraction
In Desmos, type 180-47 and press enter.
Connect it to the diagram
The value shown is the measure of in degrees because is supplementary to .
Step-by-step Explanation
Use a supplementary-angle relationship
Because the angle and form a straight line, they are supplementary:
Solve for
Subtract from both sides:
Therefore, .