Find the measure of an angle that is half as large as its complement.

1 Answer

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lfryerda | High School Teacher | (Level 2) Educator

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Two angles are complementary if they sum to 90 degrees.

Let `x` be the angle, then its complementary angle is `90-x` .  We are told that the angle is half as large as its complement, so

`x=1/2(90-x)`    multiply by 2

`2x=90-x`   move x to left side

`3x=90`   divide by 3


The angle is 30 degrees.