EXAMPLE 1 Identify complements and supplements

SOLUTION

In the figure, name a pair of complementary angles, a pair of supplementary angles, and a pair of adjacent angles.

Because 122° + 58° = 180°, CAD and RST are supplementary angles.

Because BAC and CAD share a common vertex and side, they are adjacent.

Because 32°+ 58° = 90°, BAC and RST are complementary angles.

GUIDED PRACTICE for Example 1

In the figure, name a pair of complementary angles, a pair of supplementary angles, and a pair of adjacent angles.

1.

Because FGK and HGK share a common vertex and side, they are adjacent.

Because 49° + 131° = 180°, HGK and GKL are supplementary angles.

Because 41° + 49° = 90°, FGK and GKL are complementary angles.

GUIDED PRACTICE for Example 1

Are KGH and LKG adjacent angles ? Are FGK and FGH adjacent angles? Explain.

2.

KGH and LKG do not share a common vertex , they are not adjacent.

FGK and FGH have common interior points, they are not adjacent.