Answer:
2 rays: Two examples of rays are AB and AC, both emanating from a common endpoint A and extending infinitely in opposite directions.
2 line segments: Two examples of line segments are AB and CD, both of which have two endpoints and a finite length.
2 lines (not including the parallel lines): Two examples of lines are AB and CD, which intersect at a point E.
2 sets of parallel lines: Two examples of sets of parallel lines are AB and CD, and EF and GH, where AB and CD are parallel to each other, and EF and GH are parallel to each other.
2 acute angles (not incl. the ones in the As): Two examples of acute angles are ∠BAC and ∠EFG, both of which measure less than 90 degrees.
2 obtuse angles (not incl. the ones in the As): Two examples of obtuse angles are ∠PQR and ∠XYZ, both of which measure greater than 90 degrees.
2 right angles (not incl. the ones in the As): Two examples of right angles are ∠ABC and ∠EFG, both of which measure 90 degrees.
2 clear examples of supplementary angles: Two examples of supplementary angles are ∠ABC and ∠DEF, and ∠PQR and ∠RST, where the sum of the angles in each pair is 180 degrees.
2 clear examples of complementary angles: Two examples of complementary angles are ∠ABC and ∠PQR, and ∠DEF and ∠RST, where the sum of the angles in each pair is 90 degrees.
2 clear examples of more than two angles on a line that add up to 180°: Two examples of sets of angles on a line that add up to 180 degrees are ∠ABC, ∠BCD, and ∠CDE, and ∠PQR, ∠QRS, and ∠RST.
2 right triangles: Two examples of right triangles are ΔABC and ΔPQR, where ∠CAB and ∠QRP are right angles.
2 acute triangles: Two examples of acute triangles are ΔDEF and ΔGHI, where all angles are acute.
The sum of the measures of angles within each triangle:
In ΔABC, the sum of the measures of the angles is 180 degrees, where ∠A measures 90 degrees, and ∠B and ∠C measure 45 degrees each.
In ΔPQR, the sum of the measures of the angles is 180 degrees, where ∠P and ∠R measure 90 degrees each, and ∠Q measures 0 degrees.
In ΔDEF, the sum of the measures of the angles is 180 degrees, where all angles are acute, and ∠D, ∠E, and ∠F measure 60 degrees each.
In ΔGHI, the sum of the measures of the angles is 180 degrees, where all angles are acute, and ∠G, ∠H, and ∠I measure 40 degrees each.
In ΔJKL, the sum of the measures of the angles is 180 degrees, where ∠K measures 90 degrees, and ∠J and ∠L measure 45 degrees each.
In ΔMNO, the sum of the measures of the angles is 180 degrees, where ∠O measures 90 degrees, and ∠M and ∠N measure 45 degrees each.