The people of Bridgetown wanted to build a bridge across a nearby river. Since they were poor swimmers, their master Trigonomos agreed to measure the width of the river without actually crossing it.
Trigonomos spotted a tree across the river and marked the spot directly across from it. Then he walked to another point $10$ meters down the river and found that the angle between his side of the river and the line connecting him to the tree was $40^\circ$.
**What is the width of the river?**
*Round your final answer to the nearest hundredth.*
[[☃ numeric-input 1]] meters
