133k views
3 votes
Pls help with this area question

Pls help with this area question-example-1
User Orazio
by
3.1k points

1 Answer

5 votes

Answer:

1

Explanation:

The lateral area of a cylinder is ...

LA = 2πrh

The total area is that added to the areas of the two circular bases:

A = 2πr² +2πrh

We want the ratio of these to be 1/2:

LA/A = (2πrh)/(2πr² +2πrh) = h/(r+h) = 1/2 . . . . cancel factors of 2πr

Multiplying by 2(r+h) gives ...

2h = r+h

h = r . . . . . subtract h

So, the desired ratio is ...

h/r = h/h = 1

The ratio between height and radius is 1.

User Nick Heer
by
3.6k points