What is the complementary angle of 55 degree?
2011
What is the complementary angle of 55 degree?
Answer: D. 35 degree — Two angles are complementary when the sum of their measures equals 90 degrees. Let the complement of 55 degrees be x. By definition, x + 55 degrees = 90…
- A.
180 degree
- B.
90 degree
- C.
125 degree
- D.
35 degree
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Correct answer: D
Two angles are complementary when the sum of their measures equals 90 degrees.
Let the complement of 55 degrees be x. By definition, x + 55 degrees = 90 degrees.
Solve for x: x = 90 degrees minus 55 degrees = 35 degrees.
Check: 35 degrees plus 55 degrees equals 90 degrees, confirming the pair is complementary. By contrast, the supplementary angle of 55 degrees would instead satisfy y + 55 degrees = 180 degrees, giving y = 125 degrees, a different relationship.
Hence, the complementary angle of 55 degrees is 35 degrees.