"Let x be the distance from the base of the plateau to you. Draw the situation as shown: [Triangle]

Since x is the side adjacent the 77° angle and we are given the length of the side opposite the angle, then we can use the tangent ratio to write: \(\displaystyle{\tan{=}}\frac{{{o}{p}p}}{{a{d}{j}}}\)

\(\displaystyle\frac{{ \tan{{77}}^{\circ}}}{{ \tan{{60}}^{\circ}}}\)

\(\displaystyle{x}=\frac{130}{ \tan{}}\)

\(x = 30\ m\)