A linear pair is supplementary.
It always helps to draw out a diagram with the information you have - it makes the solving process more visual and sometimes easier. I have attached a diagram of this linear pair.
So, since a linear pair is supplementary, we know these two angles add to equal 180°. Let's write this in an equation.
(5n + 15) + (4n + 21) = 180
Solve for n.
(5n + 15) + (4n + 21) = 180
5n + 15 + 4n + 21 = 180
9n + 36 = 180
9n = 144
n = 16
We're not done yet - now we have to plug this in for n to find the angle measures.
5n + 15
5(16) + 15
80 + 15
95
4n + 21
4(16) + 21
64 + 21
85
Lastly, check your work by adding the angle measures.
95 + 85 = 180
Answer:
m∠EFG = 95°
m∠GFH = 85°
