What are adjacent angles?

What are adjacent angles?

• A. Two angles that share a common vertex and side, but have no common interior points.
• B. Two angles that sum to 90 degrees.
• C. Two angles whose sum is 180 degrees.
• D. A polygon with four right angles.

Answer: (A)

Adjacent angles are two angles that share a common vertex and a common side, and their interiors do not overlap. In other words, they sit next to each other along that shared side, so no part of one angle lies inside the other. This exactly describes the situation where the two angles meet at the same corner and share one ray as a boundary, but don’t overlap. Notes to connect ideas: angles that sum to 90 degrees are called complementary, and those that sum to 180 degrees are called supplementary. Adjacent angles can have these sums, but adjacency itself just means they are next to each other with no overlap. A polygon with four right angles is a rectangle, which isn’t the concept of adjacent angles.

Adjacent angles are two angles that share a common vertex and a common side, and their interiors do not overlap. In other words, they sit next to each other along that shared side, so no part of one angle lies inside the other. This exactly describes the situation where the two angles meet at the same corner and share one ray as a boundary, but don’t overlap.

Notes to connect ideas: angles that sum to 90 degrees are called complementary, and those that sum to 180 degrees are called supplementary. Adjacent angles can have these sums, but adjacency itself just means they are next to each other with no overlap. A polygon with four right angles is a rectangle, which isn’t the concept of adjacent angles.