Correct answer: [tex]b = \frac{2A}{h}[/tex], first option.
[tex]A=\frac{bh}{2}[/tex]
[tex]2*A=\frac{bh}{2}*2[/tex] | multiply both sides by 2, 2's cancel out on the right.
[tex]2A=bh[/tex]
[tex]\frac{2A}{h} =\frac{bh}{h}[/tex] | divide h on both sides, h's cancel out on the right
[tex]b = \frac{2A}{h}[/tex]
