If three adjacent angles in the diagram form a straight angle, we know that that the sum of their measures equals 180^(∘).
∠ FGL=10^(∘), ∠ KGJ=80 ^(∘)
Practice makes perfect
Let's consider the given diagram.
We see that we have three adjacent angles that sum to the straight angle ∠ JGF. Therefore, the sum of their measures equals the measure of ∠ JGF — 180^(∘). Let's write this fact as an equation for x. Also, note that the measure of ∠ KGL is 90^(∘).
x^(∘)+ 90^(∘) + 8x^(∘) = 180^(∘)
Let's solve the above equation!