What solid is generated when the right triangle is rotated about the line? a) triangular pyramid b) cone c) cylinder d) triangular prism

B) Cone

Step-by-step explanation:

Given a right triangle being rotated about the line.

without loss of generality, assume the left corner vertex is the origin and the horizontal line is x axis

WE have the line equation of the form y =mx which is rotated about x axis.

The top vertex forms a circle when rotated about x axis.  The origin becomes invariant, in other words, origin remains a point even after rotation.  

So we get a figure with top a point and base a circle symmetrical about middle line

This is nothing but a cone.

ratio is 2 : 9

the answer is three

13.5 : 3