It would be C. A perpendicular slope means it has the opposite reciprocal slope, so 1/2 would turn into -2. Since there's only one option with -2 as a slope, C must be right.
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The square roo it 7.07106781 i
To convert a faction to a decimal you have to divide the denominator into the numerator.
1 ÷ 2 = 0.50
