Answer: 1. x= 20 units, 2. x= 
 units 3. x= 
 units.
Explanation:
In a right triangle, 
 (Pythagoras theorem)
1. Hypotenuse = x , Base = 16, Perpendicular = 12

2. Hypotenuse = 14 , Base = 11, Perpendicular = x

3. Hypotenuse = 9 , Base = x, Perpendicular =7
