By using the formula:

d² = (x₂ - x₁)² + (y₂ - y₁)²

To calculate distance between the points (x₁ , y₁) and (x₂ , y₂)

Here we have;

x₁ = 0, x₂ = - 5

y₂ = 5, y₂ = 0

d² = [( - 5) - 0]² + [0 - 5]²

d= √50= 5√2

So the distance between (0, 5) and ( - 5, 0) = 5√ 2