Answer
5.557 cm. 16.115 cm
Work Step by Step
We know that the base of the triangle is (2x+4), while the height is x. This gives:
$$ A = .5bh$$
$$42 = .5(x)(2x+4)$$
$$ 0 = x^2+2x-42$$
We know that:
$$x= \frac{-b \pm \sqrt{b^2-4ac}}{2a}$$
We simplify:
$$x= \frac{-2 \pm \sqrt{2^2-4(1)(-42)}}{2(1)}$$
We only consider the positive values:
x=5.557 cm
We plug this in to find the other value:
2(5.557)+4 = 16.115 cm
