Perimeter is the sum of all the sides .The given sides are : 10a-4 ,6a+8,6a+8,12a
The given perimeter is 102 .We can form an equation:
10a-4+6a+8+6a+8+12a=102
Adding like terms :
34a +12=102
Subtracting 12 both sides:
34a= 90
Dividing by 34 both sides:
a=-2.65.
The given sides are :
6a+8= 23.9
12a= 31.8
10a-4=22.5
Among these 31.8 is the largest side .
So the side having 12 a length is largest.
