Answer :

Anjel1521
7 3/4 centimeters long. 4 1/2 x 2= 8 1/2 (width of both sides combined)   24 - 8 1/2= 15 1/2 (length of both sides combined) 15 1/2 divided by 2= 7 3/4 (length of one side)
Albina
P=24(cm)
width= 4 1/2 (cm)
P=(a+b)*2=24
a - width
b - length
4.5+b=24/2=12
b=12-4.5
b=7,5
Well, length is 7.5 cm