When the arch collapses, it leaves the headland on one side and a stack (a tall column of rock) on the other.
The stack will be attacked at the base in the same way that a wave-cut notch is formed. This weakens the structure and it will eventually collapse to form a stump.
hope this heLps
<em>The answer you are looking for is: </em>
<em><u>r=2.67</u><u></u><u> </u>
</em><u><em></em></u><u><em></em></u><u><em>Then </em></u>
<u><em>r=3</em></u><u><em></em></u><u><em> </em></u>
<u><em>Because you round up</em></u>
<em>Hope that helps!! </em>
<em>Have a wonderful day!!</em>
I would think a galaxy, i would have a better answer if given a set of answers to choose from but hopefully this helps.