If two sides in one triangle are proportional to two sides in another triangle and the included angle in both are congruent, then the two triangles are similar.
You need to show that two sides of one triangle are proportional to two corresponding sides of another triangle, with the included corresponding angles being congruent.
You subtract $44 from $100 since that is the cast of the jeans. Then get left remaining with $56. Since he wants to buy 2 shirts only you divide 56 by 2 to then equaling $28. So then each shirt is $28.