I cannot draw a picture, so will use a thousand words instead.
Draw a horizontal line (the $x$-axis, say). Now draw a line, say through the origin, sloping fairly gently upwards. An angle of $6^\circ$ may not sound like much, about a $1$ foot rise every $10$ feet. But it is not much fun at the end of a race.
Some distance along the line, draw a point $B$, the bottom of the tower. The tower is a vertical line. Let its top be $T$. The length of $BT$ is $100$.
Downhill from $B$ is one of the points where we anchor the towed. (We hope it is also anchored other places. Let this anchor point be $A$. We are told that $AB=75$.
Finally, join $A$ and $T$ by a straight line. You are asked to find the length of $AT$.