Can someone please help me with this question?

12

Step-by-step explanation:

You simplify root 72 as much as possible which would be root 36 times root 2.

This would have then equaled 6 root 2.

You do 6 × root 2 × root 2.

This would then be 6 × 2, which would then equal 12.

Hope this helps :)

why can't you?

step-by-step explanation:

i belive those are the ones that are under 90 degreese.