Abird is flying 100 feet off the ground. looking down at a 45° angle, it sees a mouse standing still. approximately how far will the bird have to fly to catch the mouse?

The situation is describe on picture. 
We can use relations in two 45-degree angles triangle.
In this example a=100 feet and the distance which bird have to fly to catch the bird is a* \sqrt{2} [/tex] so substituting our data we have: 100* \sqrt{2} [/tex]
So  the distance is about 141,4213562 feet.