Fatima wants to mail three parcels to three village schools . She finds that the postal charges are Rs 20 , Rs 28 and Rs 36 respectively . If she wants to buy stamps only of one denomination , what is the greatest denomination of stamps she buys to mail the tree parcels ?

Tan m = opposite               m
                       =      --
              adjacent               p

just keep in mind that
when you want to know sin, cos or tan for certain angle the best way to do it is simply flip the shape so its hard edge is looking directly at you like in the figure.
the opposite and the adjacent sides are the sides coming out to meet the hypotenuse meaning look at the diagram you see line m and p going out from the 90-degree triangle or simply look at the direction of the edge of the 90 degrees is pointing at its pointing at n and also the hypotenuse is the longest side to know the adjacent and the opposite is simple adjacent is the side beside the angle and the opposite angle is explaining its self.
wishing you best luck
keep going on and believe in your self