Answer:
r = 7 mm
Explanation:
given:
A cone that has volume 1026.25mm^3 and height 20mm.
Find:
the radius of the cone
solution:
volume of a cone = 1/3 π r² h
where
vol = 1026.25 mm³
h = 20 mm
plugin values into the formula:
vol. = 1/3 π r² h
1026.25 = 1/3 π r² (20)
r² = 1026.25
1/3 π (20)
r =

r = 7 mm
therefore,
the radius of the cone = 7 mm