To find out how far Rachel walked round trip, we first need to find out how long the fastest way between her house and the park is. In the picture, we see a common Pythagorean Triple (the possibility for the sides of a right triangle). The triple with 3 and 4 is 3, 4, and 5. That means that the last side is 5. That means that the total distance is 3 + 4 + 5 km or 12 km. But, if you would like to solve this using the Pythagorean Theorem, one can do it as follows. Since the legs of the triangle are 3 and 4, the hypotenuse squared would be 3² + 4² = 9 + 16 = 25. To find the hypotenuse, we have to find the square root of 25 which is 5, which leads us to the same answer as before.
