Answer:
20.2 miles
Step-by-step explanation:
This can be described by the three sides of a right angled triangle. Let the distance of the glider to the airport be represented by x, applying the Pythagoras theorem:
=
+
=
+
576 = + 169
= 576 - 169
= 407
x =
= 20.1742
x = 20.2 miles
The glider has to fly 20.2 miles to return to the airport.