Alright, lets get started.
Please refer the diagram I have attached.
The red line indicates the movement of student.
The movement of bird is indicated by orange line.
There will a right angle triangle made with sides measuring
One side will be = 0.5 miles
second side will be =
![1 - 0.2 = 0.8 miles](https://img.qammunity.org/2019/formulas/mathematics/college/wjtbal5hxq437h4m20mfzzu6m31bx6v2m2.png)
The hypotenuse will be the orange one
So, using Pythagorean theroem,
![c^2 = a^2 + b^2](https://img.qammunity.org/2019/formulas/mathematics/high-school/fjr08nt1y8owbdv9xgos29wfe3bki2kjlb.png)
![c^2 = 0.5^2 + 0.8^2](https://img.qammunity.org/2019/formulas/mathematics/college/rwjvk5vr8j5hobqijm7z2sdjh6jnpnexjb.png)
![c^2 = 0.25 + 0.64](https://img.qammunity.org/2019/formulas/mathematics/college/u9p32ynrki1fnt4hyg1bm6wz2z4riy0byz.png)
![c^2 = 0.89](https://img.qammunity.org/2019/formulas/mathematics/college/oao5jmjgjcvgg3iheinjmfimsxlmaewzgp.png)
Taking square root on both sides
![c = 0.94](https://img.qammunity.org/2019/formulas/mathematics/college/7sn8gkpmty4zwqhc9y8j4jeh5zou908x9m.png)
So the bird has to fly 0.94 miles . : Answer
Hope it will help :)