The sale price S (in dollars) of an item is given by the formula
S=L−rL , where L is the list price (in dollars) and r is the discount rate.
Since, S = L -rL
rL = L -S
r = 
r = 
Since, the listed price of the shirt is $30, we have to find the discount rate.
Therefore, r =
is the discount rate.
It’s 180-135 which equals 45 so it is 45 degrees for X