Question

In the diagram below, GH is parallel to DE . If GH is 3 more than EH FH=10, and DE=12 find the length of EH. Figures are not necessarily drawn to scale. State your answer in simplest radical form, if necessary.

Answer 1

Answer: 5

Step-by-step explanation:

Since $\overline{GH} \parallel \overline{DE}$, by the corresponding angles theorem, $\angle FGH \cong \angle FDE, \angle FHG \cong \angle FED$. This means $\triangle FGH \sim \triangle FDE$ by AA.

As corresponding sides of similar triangles are proportional,

$\frac{10}{x+3}=\frac{10+x}{12}\\(10)(12)=(10+x)(x+3)\\120=x^{2}+13x+30\\x^{2}+13x-90=0\\(x+18)(x-5)=0\\x=-18, 5$
However, as distance must be positive, we consider the positive solution, x=5.

Therefore, the answer is 5