The formula for a triangle is 1/2bh, because b*h is the formula for a rectangle, and a triangle is half a rectangle, no matter what size. And what's another way to write "no more than a number"? \(\leq\)x, or less than or equal 2 x. Now we have both things we need for the answer to this problem.
1/2bh\(\leq\)10 is your answer. Hope this helped!
