If a pentagon is regular, then all of the sides are the same length. This means that

So, if
, the lengths of the sides evaluate to

So, all the sides of the pentagon are 21 units long, and AB is 21 units long as well, because all sides are the same length.
1/6 = 4/24
3/8 = 9/24
11/24
1/3 = 8/24
5/12 = 10/24
1/6, 1/3, 3/8, 5/12, 11/24
Service charge for Julia at a beauty salon = $72.60
The rate of sales tax taken = 8%
Percentage of tips she added to the service charge before sales tax = 20%
Then amount of tips given by Julia = (20/100) * 72.60
= (1/5) * 72.60
= 14.52 dollars
Then the amount in total paid by Julia before adding service tax = (72.60 + 14.52) dollars
= 87.12 dollars
Now the sales tax of 8% has to be calculated on the amount of $87.12.
Then
Amount of sales tax given by Julia = (8/100) * 87.12
= 696.96/100
= 6.969
= 6.97 dollars
So the total amount paid by Julia for the service at the salon = (87.12 + 6.97) dollars
= 94.07 dollars
Julia paid a total of $94.07 for the service she received at the salon.