I wasn't sure if this was the question you actually wanted because you missed off the end of your last question so i just wrote a quick solution, i'll make a more in depth solution now.
Area of a circle =πr^2, where π is a constant
This means that when the radius of the circle is increased the area of the circle will simply by increased by the multiple it was increase by squared, so in this case the radius is multiplied by 5 so the area is multiplied by 5^2=25
