Respuesta :
A = 1/2 *b*h
multiply both sides by 2
2A = b*h
divide both sides by b
2A/b = h
choice A
[tex]\dfrac{1}{2}bh=A\qquad|\text{multiply both sides by 2}\\\\bh=2A\qquad|\text{divide both sides by}\ b\neq0\\\\\boxed{h=\dfrac{2A}{b}}\to\boxed{a.}[/tex]