Which of the following statements about a rhombus is not true? A rhombus is a parallelogram.
A rhombus has two sets of parallel sides.
A rhombus has four sides of equal length.
A rhombus has four right angles.

Which of the following statements about a rhombus is not true?

All rhombuses have four sides of the same length is the statement that is not true.

(a) the volume of the cone is 20/3 in3

hence, option a is correct.

i think it would be 42cm