To find the missing side, use the equation a^2+b^2=c^2. You would plug 5 in for a to get 25 and 8 in for b to get 64. You would add those to get that 89 is equal to c^2 so you would get c by itself and and find that the answer is D. :)
Has 33 now. Before adding 13 stamps, she had (33-13) 30. This is half of her total, since she already sold half. To get the whole, multiply 30 by 2. 60 She started with 60
