Direction Tests

A man leaves for his office from his house. He walks towards East. After moving a distance of $20\mathit{m}$. he turns towards South and walks $10\mathit{m}$. Then he walks $35\mathit{m}$ towards the West and further $5\mathit{m}$ towards the North. He then turns towards East and walks $15\mathit{m}$. what is the straight distance in metres between his initial and final positions?