Question

a cube has a diagonal of 6. how long is one edge of a cube?

Answer 1

36=2c^2
c = sqrt18
c =3sqrt2

Answer 2

for some reason, the answer sheet says it's 2 square root of 3. :| is it wrong?

Answer 3

wait a minute i did a lil wrong it's a cube i took it as square

Answer 4

okay got it side = sqrt12 = 2sqrt3

Answer 5

first the face diagonal = sqrt2xside
then when we apply Pythagoras = 3c^2 =36 =>c=sqrt12

Answer 6

i'm so sorry but i got lost in your explanation.

Answer 7

okay actually this is 3d so it gets complicated but it's okay

okay now face diagonal imagine a square the diagonal is sqrt2c
if c is side of the cube

Answer 8

now in a cube diagonal a facediagonal and a side are involved
facediagonal is sqrt2c and the side is c
that makes cube diagonal = sqrt(2c^2 +c^2)

now cube diagonal is 6
hence

36 = 3c^2
c = sqrt12
c=2sqrt3

Answer 9

now if your still unable to understand draw a diagram and then go through this whole process again