The ratio of the width to the length in a certain rectangle is 5:8. If the length of the rectangle is 12 cm, what is the width?

1 Answer
Mar 28, 2018

#7.5# cm

Explanation:

The ratio is:
#w/l = 5/8#

Since the rectangle shares this ratio we can also say:
#w/l = x/12# where #x# is the length of the side we do not know.

So, using substitution:
#5/8 = x/12#

Now use cross multiplication to simplify. The ones we are multiplying together are colored the same:
#color(blue)5/color(green)8 = color(green)x/color(blue)12#

#8 xx x = 5 xx 12#

#8x = 60#

#x =7.5#

So, the width is #7.5# cm