Answer:
The value of 'x' is 31 unit
Step-by-step explanation:
Given:
Measure of each side = 
Perimeter of sails = 63 units.
We need to find the value of x.
Solution:
Now we can see that from given data.
A sailboat's Saul has three sides.
Now assuming it to be triangle we get;
"Perimeter of triangle is equal to sum of all side."
So we can say that;

Now adding both side by 30 we get;

Now dividing both side by 3 we get;

Hence the value of 'x' is 31 units.