geometry
posted by Lydia .
if 6, 10, and 12, and 9, and x are the lengths of the coresponding sides of two similair triangles, what is the value of x?

You have provided 4 lengths and an unknown x.
Two triangles require six sides. Did you omit one side length?
If one triangle has side lengths of 6,10 and 12, then the other similar triangle side lengths could be 9, 15 and 18, but it would depend upon which side of the first triangle corresponds to the 9 of the second triangle. 
Sorry,
if 6, 10, and 12, and 9, 15 and x are the lengths of the coresponding sides of two similair triangles, what is the value of x? 
In that case, I assumed the fifth correctly and x = 18

thanks!

what kind of triangle has sides of lenght 12,16,24?