One advantage is that you don't have to count out your money when you are cashing in. But one con is that people can forge your signature if you give it to them and their dishonest.
When Peter does this, he is creating two sides of a right-angle triangle. The distance from his house to that point will be the hypotenuse of the triangle thus, to work out the length of the hypotenuse, we have to use Pythagoras Theorem! So:
a² + b² = c²
15² + 15² = c²
225 + 225 = c²
450 = c²
15√2 = c
21.21320344 = c
So, this rounded to the nearest tenth would be:
21.2 meters !
Add them all together and multiply by 2
