The triangles are similar because they have the same internal angles. That is,
∠S ≅ ∠U
∠T ≅ ∠T
∠R ≅ ∠V
Given that they are similar, then their sides are in proportion, as follows:
[tex]\frac{SR}{UV}=\frac{RT}{TV}[/tex]
Replacing with data and solving for x,
[tex]\begin{gathered} \frac{1.7\text{ m}}{x\text{ m}}=\frac{1.2\text{ m}}{31.5\text{ m}} \\ 1.7\cdot31.5=1.2\cdot x \\ 53.55=1.2\cdot x \\ \frac{53.55}{1.2}=x \\ 44.625\text{ m =x} \end{gathered}[/tex]
