The width of a rectangle is 2/5 its length. Find the dimensions if the perimeter is 42

meters.

The formula to find the perimeter of a rectangle is P = 2 (l+w). By substituting what we now knowin to the equation:

•42=2 (l + (2/5l)). We can have width represented at (2/5l) because it's now 2/5 of the length. Now add them together to get a single coefficient for l.

•42 = 2 (7/5l). Multiplying 7/5 by 2.

42 = (14/5l). Multiplying both sides by the reciprocal of 14/5, which is 5/14, to get l by itself.

•l = 15.

Now that we now know the value of l, we know that the length is 15m. To find the width of the answer, we then multiply 15 by 2/5, which equals 6. Therefore, the only third option is correct because the length is 15m and the width is 6m.