Answer:
The base is 27 units long.
Step-by-step explanation:
This is a solve the system question. Call the length of the base B and the length of each leg L. We are told:
[tex]B=1.5L[/tex]
and
[tex]B+2L=63[/tex]
Sub the first equation into the second:
[tex]1.5L+2L=63\\3.5L=63\\L=18[/tex]
Now that we have the leg length, sub that into either of the original equations to find the base. I'll use the first equation:
[tex]B=1.5(18)\\B=27[/tex]