A man walks 10 km South, then turns left and walks 5 km, then turns left again and walks 10 km. How far is he from the starting point?

Explanation

• Start at (0,0)
• Walk South 10 km: (0,-10)
• Turn left (facing East), walk 5 km: (5,-10)
• Turn left (facing North), walk 10 km: (5,0)
• Distance from start = 5 km