Answer :
Since the ratios are defined by proportional relationships, we can use proportional relationships to find the measre of the base, and then use pythagorean theorem to find l:
[tex]\begin{gathered} \frac{12}{1}=\frac{x}{0.8} \\ x=0.8\cdot12 \\ x=9.6\text{ m} \end{gathered}[/tex]The base of the triangle would be 9.6, now we can calcualte l by the pythagorean theorem:
[tex]\begin{gathered} c^2=a^2+b^2 \\ l^2=0.8^2+9.6^2 \\ l=\sqrt[]{0.64+92.16} \\ l=\sqrt[]{92.8} \\ l\approx9.63 \end{gathered}[/tex]The length of the ramp is 9.63 m