Answer: A.
Step-by-step explanation: Your marked answer is correct but unless you want full details, here it is:
1. From the smaller triangle's hypotnuse 5 => 10 is 5(2) = 10. So take the other sides and double it up and you will get x=6 and y=8.
2. But if you are still not sure, follows the steps to find the hypotnuse:
x (squared) + y (squared) = the prefect square of the sum.
So that means : 6 ( squared ) = 36 | 8 ( squared ) = 64 | 64+36 = 100 | And perfect square of 100 is 10.
So that's why A. is the correct answer
