The distance between the points (d) is found using the Pythagorean theorem.
Imagine the two points as defining the hypotenuse of a right triangle. The lengths of the legs of the triangle are the horizontal distance between the points and the vertical distance between the points. The the theorem tells us d² = 4² + 7² d² = 16 + 49 d² = 65 d = √65 ≈ 8.1
The distance between the points is C 8.1
_____ You know that the distance must be longer than the longest leg (7) and must be shorter than the sum of the two legs (4+7=11). The only answer choice between 7 and 11 is 8.1.