Answer:
11.4
Explanation:
You want the distance between C(-5, 5) and D(4, -2).
Distance
The distance formula is ...
d = √((x2 -x1)² +(y2 -y1)²)
For the given points, the distance is computed to be ...
d = √((4 -(-5))² +(-2 -5)²) = √(81 +49) = √130
d ≈ 11.4
The length of CD is about 11.4 units.
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Additional comment
The distance formula is an application of the Pythagorean theorem. It computes the hypotenuse of a right triangle whose legs are the differences in x- and y-coordinates.