The figure shown is a question of similar triangles.
I will be breaking the figure down into a small triangle and a bigger triangle.
By similarity, we compare similar sides of the triangle
Side MX = x
[tex]\begin{gathered} \frac{3.5}{x}=\frac{17.5}{x+12} \\ \text{Cross multiplying, we have} \\ 17.5x=3.5(x+12) \\ 17.5x=3.5x+42 \\ 17.5x-3.5x=42 \\ 14x=42 \\ x=\frac{42}{14} \\ x=3 \end{gathered}[/tex]
Therefore, the length of the side MX is 3cm. (Option A)
