Question

You are given that <GHJ is a complement of <RST and <RST is a supplement of <ABC. Let m<GHJ be x°. What is the measure of < ABC?

Answer 1

∠GHJ and ∠RST are complementary

⇒  ∠GHJ and ∠RST = 90°

And ∠RST and ∠ABC are supplementary

⇒  ∠RST and ∠ABC = 180°

Also, ∠GHJ = x°

⇒ ∠RST = 90° - x°

⇒ ∠ABC = 180° - ∠RST

⇒ ∠ABC = 180° - (90° - x°)

⇒ ∠ABC = 90° + x°