ANSWER
65 km
Step-by-step explanation
Let's do a diagram of the path Harold took,
As we can see, the path forms a right triangle where the shortest distance from the starting point, d, is the hypotenuse. Using the Pythagorean theorem we can find d,
![d=\sqrt[]{33^2+56^2}=\sqrt[]{1089+3136}=\sqrt[]{4225}=65](https://img.qammunity.org/2023/formulas/mathematics/college/to3dvn05ybneth1pj1qkhtfxo6s5algk5n.png)
Hence, the shortest distance from his starting point is 65 km.