Question

What is the value of c in the figure below? If necessary, round your answer to the near test tenth of a unit

Answer 1

Ok, so

We got the next triangle:

We know that ∆CDA ~ ∆CAB ~ ∆DBA. This means that triangles CDA and ADB are congruent.

Knowing this, we could make the next relation applying the geometric mean theorem:

$\frac{15}{x}=\frac{x}{4}$

Now, we multiply by cross:

$\begin{gathered} (15)(4)=(x)(x) \\ 60=x^2 \\ \sqrt[]{60}=x \\ 7.7\cong x \end{gathered}$

Finally, x measures 7.7.