Answer:
5
Explanation:
The horizontal distance between the points is 3 units; the vertical distance is 4 units. The straight-line distance is the length of the hypotenuse of a right triangle with those side lengths. So, the distance between the two points is ...
√(3² +4²) = √(9+16) = √25 = 5 . . . . units
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Comment on this triangle
The numbers 3, 4, 5 are the smallest set of integers that satisfy the relation of the Pythagorean theorem. They are also the only set of sequential numbers or numbers in arithmetic sequence that satisfy the Pythagorean theorem. As a consequence, they show up often in geometry and algebra problems. The "3-4-5 triangle" is worth remembering. So, anytime you see numbers that have these ratios, such as 9, 12, 15, for example, you know they can be the sides of a right triangle.