Transversal of parallel lines

transversal is a line that intersects two other lines.

Two angles formed by a transversal crossing two lines are corresponding angles if they are in matching corners.

Two angles are supplementary angles if their measures add up to 180°.

ABD and ∠DBC are supplementary angles.

Learn with an example

Check each pair of angles.

OPM and ∠LMP are not corresponding angles. They are not in matching corners.

OPM and ∠LMK are corresponding angles. They are in matching corners.

OPM and ∠OPR are not corresponding angles. They are not in matching corners.


OPM and ∠NMP are not corresponding angles. They are not in matching corners.

First find ∠FEH.

Check each pair of angles.

FEH and ∠DEH are supplementary angles. Their measures add up to 180°.

FEH and ∠DEC are not supplementary angles. Their measures do not add up to 180°.

FEH and ∠GHE are not supplementary angles. Their measures do not add up to 180°.

FEH and∠ IHJ are not supplementary angles. Their measures do not add up to 180°.

First find ∠LKH.

Check each pair of angles.

LKH and∠ LKM are supplementary angles. Their measures add up to 180°.

LKH and ∠JKM are not supplementary angles. Their measures do not add up to 180°.

LKH and ∠GHK are not supplementary angles. Their measures do not add up to 180°.

LKH and ∠IHF are not supplementary angles. Their measures do not add up to 180°.

let’s practice!