Adjacent angles are one of the earliest and most important concepts to learn in basic geometry, as they have applications in further subjects like trigonometry, physics, and engineering.

Learn about complementary, supplementary, corresponding, alternate and vertically opposite angles with BBC BItesize Scotland maths for Third Level CfE.

Vertically opposite angles are equal, so angle 𝒙 = 140°. Angle 𝒚 and 70° are adjacent angles on a straight line. Adjacent angles on a straight line add up to 180°, so angle 𝒚 = 110° .