Which of the following expresses 12 + 42 by using the GCF of the two numbers? 3(9 + 14)
3(4 + 38)
6(2 + 7)
6(6 + 36)

according to the triangle sum theorem, all the angles in a triangle must add up to 180 degrees. if we know one angle is already 90, we do 180-90=90. the other 2 angles must add up to 90, exactly.

step-by-step explanation:

step-by-step explanation:

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