7. 12*5/2=30in^2 (greater than 15 square inches)
8.5*4/2=10in^2 (less than 15in^2)
9.14*5/2=35in^2 (greater than 15in^2)
10. I have no clue on this one, sorry.
11. 20*7/2=70in^2 (greater than 15in^2)
(I think)
12. 12^2-4^2=144-16=128 (that will be 8√2)
And find the Areas
A=4*8√2/2=16√2
And then find the area of the small triangle.
A=4*(8√2-8)/2=(32√2-32)/2=16√2-16
Now minus the area of small triangle area from the big triangle area.
16√2-(16√2-16)=16√2-16√2+16=16in^2 (greater than 15in^2)
So the Numbers that is greater than 15in^2 are 7,9,11,12
