Perimeter of a rhombus=4s(4*side)diagonals intersect at midpoints(o) and they form right angles...BC^2=BO^2+CO^2 =9^2+18^2 =81+324 =405BC=√405cms(can do further simplification)

The diagonals of a rhombus intersect each other at their midpoints and cross at right angles. Thus, we can use the Pythagorean Theorem to determine the length of one side.

(side) = √((18 cm/2)^2 + (9 cm/2)^2)

= (9/2 cm)√(2^2 + 1^2)

= (9/2 cm)√5

The perimeter is the sum of the lengths of the 4 equal sides, so it will be

(side) = √((18 cm/2)^2 + (9 cm/2)^2)

= (9/2 cm)√(2^2 + 1^2)

= (9/2 cm)√5

The perimeter is the sum of the lengths of the 4 equal sides, so it will be

**perimeter**= 4*(9/2)√5 cm**= 18√5 cm**