The lengths of the diagonals work out as 12 cm and 16 cm
That will depend on the lengths of the diagonals of the rhombus which are of different lengths and intersect each other at right angles but knowing the lengths of the diagonals of the rhombus it is then possible to work out its perimeter and area.
Add up the lengths of all the sides.
That would be "perimeter". The perimeter is the distance around a figure, and it is calculated by adding the lengths of the different sides. For example, for a triangle, add the lengths of the three sides.
It depends on what information you have: the length of a side, or the lengths of the diagonals, or a diagonal and an angle. Each of these will give rise to a different formula.
The lengths of the diagonals work out as 12 cm and 16 cm
That will depend on the lengths of the diagonals of the rhombus which are of different lengths and intersect each other at right angles but knowing the lengths of the diagonals of the rhombus it is then possible to work out its perimeter and area.
the answer is 20
The are different formulae for its perimeter, area, lengths of diagonals, angle and these depend on what information is provided.
The answer depends on what characteristic you wish to measure: the lengths of the sides, the angles, the lengths of the diagonals, perimeter, area, temperature, colour, and so on.
Add up the lengths of all the sides.
I'm some cases yes while in others no :)
Semi-perimeter means half the perimeter. Calculate the perimeter, then divide that by 2 to get the semi-perimeter.
That would be "perimeter". The perimeter is the distance around a figure, and it is calculated by adding the lengths of the different sides. For example, for a triangle, add the lengths of the three sides.
It depends on what information you have: the length of a side, or the lengths of the diagonals, or a diagonal and an angle. Each of these will give rise to a different formula.
To find the perimeter of a rectangle you must calculate the lengths of each of the sides and add them all together.
You need more information: the length of a side. Then, since the diagonals bisect one another at right angles, you can use Pythagoras's theorem to calculate their lengths.