1. ## Find DC

To measure the distance (DC) across a pond, a surveyor takes points A and B so that AB is parallel to DC. If AB = 60 feet, EB = 48 feel, and ED = 80 feet, find DC.

2. Originally Posted by symmetry
To measure the distance (DC) across a pond, a surveyor takes points A and B so that AB is parallel to DC. If AB = 60 feet, EB = 48 feel, and ED = 80 feet, find DC.
Where/what is E?

RonL

3. Hello, symmetry!

To measure the distance $DC$ across a pond,
a surveyor takes points $A$ and $B$ so that $AB \parallel DC$.

If $AB = 60\text{ ft},\;EB = 48\text{ ft},\;ED = 80\text{ ft}$, find $DC$.
You forgot to tell us where point $E$ is, but I have a good guess.
Code:
    D * - - - - - - - - - - - - - - - * C
*                       *
80 *               *
*       *
*E
*       * 48
*               *
A * - - - - - - - - - - - * B
60

From the similar triangles, we have: . $\frac{CD}{80} \:=\:\frac{60}{48}$

Therefore: . $CD \:=\:100\text{ ft}$

4. In real-life, the person helping the surveyor would go to the other side of the pond with a prism and the surveyor would measure the distance with the transit. That's no fun, though. Too easy.

5. ## ok

Thank you all, especially soroban. Soroban did a great job with the picture and reply.

Thanks!