## alternate angles

Geom. a pair of nonadjacent angles, one on each side of a transversal, that are both interior or both exterior: these paired angles are equal if the lines cut by the transversal are parallel

## alternate angles

Noun

(*plural only*)

- (geometry) the internal angles made by two (parallel) lines with a third, on opposite sides of it.If the parallels AB, CD, are cut by the line EF, intersecting at points G and H, then the angles AGH, GHD, are called alternate angles (as also are the angles BGH and GHC).