Identify complementary, supplementary, vertical, adjacent and congruent angles
Key Notes:
Vertical angles are angles formed opposite each other when two lines intersect.
Learn with an example
Which angle is vertical to ∠ AEB?
Look at ∠ AEB and ∠ CED:
∠CED and ∠AEB are vertical angles.
Which angle is adjacent to ∠AGB?
Look at ∠AGB and ∠BGD:
∠BGD is adjacent to∠ AGB.
Which angle is complementary to ∠BGC?
Look at ∠BGC and ∠CGD:
∠CGD is complementary to ∠BGC. Along with the right angle, they form a straight line. The straight line measures 180° and the right angle measures 90°. That leaves another 90°, so ∠ BGC and ∠ CGD have measures that add up to 90°.
let’s practice!