M E N U DIRECTIONS 1. USEFUL FORMULAS 2. THE CIRCLE (3 VARIATIONS) 3. THE SPHERE (2 VARIATIONS) 4. THE SQUARE (2 VARIATIONS) 5. THE CUBE (2 VARIATIONS) 6. THE RECTANGLE • 7. THE AIRPLANE 8. THE SLIDING LADDER 9. MAKING SHADOWS 10. THE CONICAL TANK 11. THE CONICAL PILE 12. FLYING A KITE 13. REVOLVING SEARCHLIGHT 14. TRAVELING CARS (2 VARIATIONS) 15. MORE SHADOWS 16. THE BASEBALL FIELD 17. THE CYLINDRICAL TANK 18. EQUATION ONE (2 VARIATIONS) 19. EQUATION TWO (2 VARIATIONS) 20. EQUATION THREE (2 VARIATIONS) 21. EQUATION FOUR (2 VARIATIONS) 22. EQUATION FIVE (2 VARIATIONS) 23. EQUATION SIX (2 VARIATIONS) 24. EQUATION SEVEN 25. THE REVOLVING BEACON 26. THE ISOSCELES TROUGH 27. THE SPACE SHUTTLE 28. GONE FISHING 29. THE CLOCK 30. THE TRIANGLE #1 31. THE TRIANGLE #2 32. THE SNOWBALL 33. THE OTHER AIRPLANE 34. YET ANOTHER SHADOW 35. THE BASKETBALL SHADOW 36. MAKING COFFEE

AIR TRAFFIC CONTROL PROBLEM An airplane is flying at an altitude of 4 miles and passes directly over a radar antenna. When the plane is 12 miles from the antenna, the radar detects that the distance is changing at a rate of 450 miles per hour. (A) What is the planes horizontal (or ground) distance from the antenna? (B) What is the speed of the plane at that moment?