angles ?

Question

Let ∠1, ∠2, and ∠3 have the following relationships. ∠1 and ∠2 are adjacent right angles. ∠1 and ∠3 are vertical angles. What is the measure of ∠1 plus the measure of ∠3 minus the measure of ∠2?

Answer 1

Grace,

If 1 and 2 are adjacent right angles, they are both 90º.

1 and 3 are vertical, which means they must be congruent, so 3 is also 90º

 

So:  90 + 90 - 90 = 90

 

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        1 |  2

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