A rectangle room is three times as long as it is wide and it perimeter is 56 m find the width of the room

Question

anonymous · Answer

$$3l=w $$

anonymous · Answer

l represents length and w represents width. Therefore, the length w is 3 times bigger than the length. The equation for perimeter is $$P=2l+2w$$

anonymous · Answer

Now just plug in the value for w in terms of l and it looks like this:
$$P = 2l+2(3l)$$

anonymous · Answer

Now remember that the given perimeter was 56m so setting P = 56 m, you get:
$$56 = 2l+6l$$

anonymous · Answer

now solve for l which is $$56 = 8l \rightarrow l=56/8\rightarrow 7$$

anonymous · Answer

you know that 3 times the length is the width, therefore, knowing the length, 3 times 7 is 21 and 21 is the width of the rectangle.