Answer:
7.8
Explanation:
You want the distance between P(8, 2) and Q(3, 8).
Distance between points
The distance between points is given by the distance formula:
d = √((x2 -x1)² +(y2 -y1)²)
d = √((3 -8)² +(8 -2)²) = √((-5)² +6²) = √61
d ≈ 7.8
The distance between points P and Q is about 7.8 units.
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Additional comment
You will notice that the desired distance is the length of the hypotenuse of a right triangle with legs that are 5 and 6. The Pythagorean theorem tells you that length is √(5² +6²) = √61, as above. The distance formula is based on the Pythagorean theorem.
You can find the relevant triangle leg lengths by counting grid squares on the graph. Of course, the distance formula does the same thing by subtracting coordinate values.