Two angles are Complementary when they add up to 90°.
Therefore m∠DFG + m∠JKL = 90°.
We have m∠DFG = x + 1 and m∠JKL = x - 9. Substitute:
(x + 1) + (x - 9) = 90
(x + x) + (1 - 9) = 90
2x - 8 = 90 add 8 to both sides
2x = 98 divide both sides by 2
x = 49
m∠DFG = x + 1 → m∠DFG = 49° + 1° = 50°
m∠JKL = x - 9 → m∠JKL = 49° - 9° = 40°
Answer: m∠DFG = 50° and m∠JKL = 40°
