Find the height of a cylinder with a surface area of 108 pi square meters. the radius of the cylinder is twice the height.

Assuming the cylinder is closed at both ends 
Surface area = 2 pi r^2 + 2 pi r h  = 108

now h = r/2 so we have:-

 2pi r^2 +  pi r^2= 108

 3 pi r^2   = 108
r^2 = 11.459
r =  3.385 
so the height h = 1.693 m to nearest thousandth

Answer: d. 39 cmin the diagram, the approximate length of the minor arc de is 39 centimetres.step-by-step explanation: the formula for the length of an arc in a circle is as displayed below.let the length of the minor arc de = xx = 2( pi )r × angle of sector / 360°from this, we will substitute the values given from the problem into the formula to obtain the length of the minor arc de.x = 2( pi )r × angle of sector / 360°r = radius = 25cmpi as an approximate value = 3.14angle of sector = 120°x = 2( 3.14 )( 25 ) × 120° / 360°x = 157 × 1 / 4x = 39.25x = 39 ( rounded to the nearest whole number as an approximate value )

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