at distance — from the plane base 3r

at distance — from the plane base 3r

at distance — from the plane base 3r

at distance — from the plane base or

right angled triangle

equilateral triangle

square

circle

h/2

J/3

h/6

h/4

same

double

half

four times

arm of man

pair of scissors

pair of clinical tongs

all of the above