The shop declare a discount of 20% and later a discount of 15% after
first discount. total discount was?

Let, the original amount = x
First discount = x * 0.20 = 0.20x

Amount after first discount = x - 0.20x = 0.80x
Second discount = 0.80x * 0.15 = 0.12x

Amount after second discount = 0.80x - 0.12x = 0.68x
Difference would be: x-0.68x = 0.32x

So, Your Answer would be 32%

Hope this helps!

Shortest side: xside two: x+26side three: 2xwork: x+x+26+2x=1304x+26=130 -26 -264x=104(4x=104)/4x=26check: 26+26+26+52=130shortest side length is 26 feet