1: The angle with 53 degrees is an acute angle. Acute angles are less than 90° (albeit greater than 0°). 53 < 90. 53 > 0.
Without knowing the degrees (°) however, one can still tell if an angle is an acute given that acutes appear to be more closed in comparison to the other angles (right and obtuse).
2: The angle with 127° is an obtuse angle. Obtuse angles are greater than 90° (albeit less than 180°). 127 < 180. 127 > 90.
One can identify an obtuse angle simply by looking at it given it's distinct trait. The distinct trait is that obtuses appear more open in comparison to the other angles (right and acute).
Think of it like a recliner chair.
[Note: The l is the mobile back of the recliner chair. The _ part is the seat.]
When the recliner chair is put upright with it's position looking like an L, it models a right angle and the degrees of it is inevitably 90°. When you move the back of the recliner chair forward, its position is shaped like ∠ with the degrees under 90° but above 0°. This is an acute. You quickly move the back way back and farther than 90°, but the limit of how far the recliner back can move is 180°. The chair's position looks like the following attachment. This is an obtuse.
3. That's complementary angles. Complementary angles are two acute angles (angles with degrees below 90, i.e 34 and 56) added together that equal a right angle (angle with 90°). 34 + 56 = 90.
4. That's vertical angles. Vertical angles are two angles that equal one another and share the same vertex.
67° = 67°
