Question

starting with the right angle triangle, explain how can you get a cone​

Answer 1

Answer:

First you draw a right angled triangle.

Then taking its base rotate it 360° perpendicularly. You will get a cone.

The picture is drawn in the attachment.

Answer 2

The solid obtained on revolving a right-angled triangle about one of its sides(other than the hypotenuse) is called a cone.

Let the right-angled triangle ABC be revolved about its side AB to form a cone;then AB is the height 'h' of the cone formed, BC is the radius 'r' of its base and AC is its slant height 'l'.

Clearly by Pythagoras theorem,

$l {}^{2} + = h {}^{2} + r {}^{2}$