Answer:
8 cm
Step-by-step explanation:
To find the length of the rectangle's base, form 2 equations using the given information.
Perimeter of rectangle= 2(height +base)
Let the lengths of the height and base of the rectangle be h and b cm respectively.
Perimeter= 80
2(h +b)= 80
h +b= 80 ÷2
h +b= 40 -----(1)
h= 4b -----(2)
Let's solve by substitution!
Substitute (2) into (1):
4b +b= 40
5b= 40
b= 40 ÷5
b= 8
Thus, the length of its base is 8 cm.
