### Home > INT3 > Chapter 9 > Lesson 9.1.3 > Problem9-34

9-34.

Yee Ping is thinking about swimming across Redleaf Lake. She knows that she can swim about $1000$ meters. She decides that she will feel more confident if she knows how far she will have to swim. To determine the length of the lake, she puts posts at both ends of the lake (points A and B) and a third post as shown in the diagram at right (point C). Use this information to determine how far Yee Ping will have to swim across the lake. Should Yee Ping be confident that she will be able to swim across Redleaf Lake?

Use the Law of Cosines to solve for the length of the lake.

The lake is about $1039$ meters wide. Would Yee Ping have a problem?