prealgebra
posted by sweetangle on .
a traffic sign is in the shape of an isosceles triangle. each of the equal sides is 5in.longer than tice the base.if the perimeter is 80in., find the length of the base?
whoever helps me can you tell me how to respond i do not know how to respond back to say thank you or ask for more help. thank you<3

SEcond remark: Use reply below.
First. Perimeter= b+L+L
Perimeter=b+5+b + 5 + b
you are given perimeter , solve for b, the base 
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oh ok ty drBob222. in order to solve this problem do i use the formula isosceles? and thank you so much for helping me!