the length of a rectangle is 3 times its breadth,if the perimeter is 84 , find the length
L = 3B
2L + 2B = 2(3B) + 2B = 84
Solve for B, then L.
10.5
To find the length of the rectangle, we need to set up a system of equations using the given information.
Let's assume that the breadth of the rectangle is x.
According to the given information, the length of the rectangle is 3 times its breadth. Therefore, the length would be 3x.
The perimeter of a rectangle is calculated by adding the lengths of all its sides. For a rectangle, the perimeter is given by the formula: P = 2(length + breadth).
In this case, the perimeter is given as 84, so we can set up the equation: 84 = 2(3x + x).
Simplifying this equation, we get: 84 = 2(4x).
Next, we can remove the parentheses by multiplying 2 with (4x): 84 = 8x.
Now, to solve for x, we divide both sides of the equation by 8: x = 84/8.
Simplifying this further, we have: x = 10.5.
Therefore, the breadth of the rectangle is 10.5.
Since the length is 3 times the breadth, the length would be 3 * 10.5 = 31.5.
So, the length of the rectangle is 31.5 units.