Answer:
13.41 cm
Step-by-step explanation:
The radius, height, and HALF of vertical angle makes a triangle.
Where
Radius will be the base of the triangle
Height will be the "height" of the triangle
Top angle will be HALF of vertical angle (40/2 = 20)
From the 20 degree angle, the side "opposite" would be the radius, which is 30. The side "adjacent" would be the height, let it be h.
Which trig ratio relates opposite and adjacent? Yes, that is TAN. Thus we can write:
Tan(20) = opposite/adjacent
Tan(20) = 30/h
h = 30/Tan(20)
h = 13.41
So
The height of the cone would be around 13.41 cm