Answer :
Let x= side 1= 19
Let y= side 2=unknown
Let z= side 3=unknown
Since it is an isosceles triangle, two sides are equal, which happen to be y and z
Hence y=z
Perimeter of a triangle = Sum of all three sides
= x+y+z
51=19+2y [since we know x=19 and y=z, we know the perimeter is 51]
Solve now
32=2y
16=y
Since y=z
z= 16
Hence the unknown side's length is 16m
Let y= side 2=unknown
Let z= side 3=unknown
Since it is an isosceles triangle, two sides are equal, which happen to be y and z
Hence y=z
Perimeter of a triangle = Sum of all three sides
= x+y+z
51=19+2y [since we know x=19 and y=z, we know the perimeter is 51]
Solve now
32=2y
16=y
Since y=z
z= 16
Hence the unknown side's length is 16m
So the perimeter is 51. The base is 19. Subtract 19 from 51. 51 - 19 = 32. So 32 is the total length of the two equal unknown sides added together. Because the two sides must be equal, you can just divide 32 by 2. 32/2 = 16. Each of the two congruent sides are 16 m.