Answer: 20%.
Step-by-step explanation:
Given, The price of a shirt is marked down from $12.50 to $10.00.
Previous price = $12.50
New price = $10.00
Change in price = Previous price - New price
= $12.50 - $10.00
= $2.50
Now, the percent decrease of the shirt = 

Hence, the percent decrease of the shirt = 20%.
54•150,I think that’s the way to do it,let me know if I’m wrong.
Step-by-step explanation:
Since SP=TR, the differnce of PR and ST 24-15 divided by 2 is the length of PD (4.5)
Try to understand the rest from the attached picture