Question 1105128
A graduated cylinder, pictured, is used to measure solutions in a laboratory. It is open at the top and closed at the bottom. 
 
On the picture 80ml cylinder
 
If a graduated cylinder has a height (h) that is 4 cm more than its radius (r) and a surface area of 16p cm2, use the equations below to calculate the diameter of the graduated cylinder. Give exact answer in fraction form.

 Area of the side of a cylinder = 2πrh
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What is 16p cm?