How to work out the perimeter of a rhombus when the diagnol of the rhombus is 98cm?

Question

the sides of the rhombus all equal the same value.

Answer 1

The measure of one diagonal is not enough to determine the perimeter of a rhombus. You'd need to know both diagonals, or an angle.

For example, the sides of the rhombus could be 1,000cm long (perimeter 4,000cm)... but it is very thin and flat and 98cm is the shorter diagonal.

Or the sides could be 50cm long (perimeter 200cm), but it is very thin and flat and 98cm is the longer diagonal.

Answer 2

You need to know the other diagonal as well, or one of the angles.