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Answer:
Explanation:
The differences of coordinates are ...
E-D = (-2, 0) -(-4, -2) = (-2+4, 0+2) = (2, 2)
The slope is the ratio of the y-difference to the x-difference:
slope of DE = ∆y/∆x = 2/2 = 1
The length is the root of the sum of the squares of those differences:
length of DE = √(2² +2²) = √8 = 2√2
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Similarly, the slope of CB is found from ...
B -C = (1, -2) -(-3, -6) = (1+3, -2+6) = (4, 4)
slope = 4/4 = 1
And the length is ...
length of CB = √(4² +4²) = 4√2
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Because the slopes of DE and CB are both 1, DE ║ CB.
DE = 2√2 and CB = 4√2.
Because 2√2 = (1/2)·4√2, DE = 1/2·CB.