Answer:
6.75cm
Step-by-step explanation:
The straw fits diagonally inside the can so it makes a right angled triangle with height and base of the can ( which is the diameter of the can)
So, hypotenuse = length of straw = 22.5cm
perpendicular = 18cm
base = diameter of can(d)
Using pythagoras theorem
h² = p² + b²
(22.5)² = 18² + d²
506.25 = 324 + d²
d² = 506.25 - 324
d² = 182.25
d = 13.5cm
Now radius = d/2 = 13.5/2 = 6.75cm
