Length and Width.
Area = Length * Width
because they need to know where to find these things
Its length and its perpendicular height Area = length*height
If you need to find how big something 2-D is you need to know how to find the area of various shapes. If carpeting you need area. You don't think about it but area is very important. Math isn't useless and is very important int he real world.
You will need to know the height before you can calculate the base form the area.
You cannot find the area of a rectangle if you only know its length. You need to know its width too. Then you multiply its length by its width.
To find the diameter of a circle, you will either need to know the area or its circumference. If you know the area: diameter = 2 x squareroot(area / Pi) If you know the circumference diameter = circumference / Pi
Google helps people find things they need to know
First, you nee to know two things. One, you need to know the length of any one side (the base). Two, you need to know the height. The height is the length of a segment perpendicular to the base. if you know those two numbers, you can plug them into the following equation: A=1/2bh, where A is the area, b is the base, and h is the height.
You can find the permeter if you know the length of the sides. You need to add the lengths of all the sides together.
To find the density of an object, you need to know its mass and volume. Density is calculated by dividing the mass of the object by its volume.
To calculate pressure, you need to know the force applied on an object and the surface area over which the force is distributed. Pressure is calculated by dividing the force by the surface area.
You would need to know the surface area of a cylinder if you are a factory worker at Pepsi. You would need to know the dimensions of the label, so it will fit on the can.