Tap 4 interior angles

Find the angles located between the two parallel lines.

Slide to match

Corresponding angles are in the same relative position. Slide the angle down to prove they are equal!

Drag to alternate

Alternate Interior angles are on opposite sides of the transversal. Drag to match!

Rotate transversal

Co-interior angles always add to 180°. Drag the center line left or right!

{{ Math.round(transAngleDeg) }}° {{ 180 - Math.round(transAngleDeg) }}°

Fill all angles

Select a value, then tap the empty spots to complete the set.

{{ s5_values[a.id] }}° ?