Answer:
19 cm
Step-by-step explanation:
The perimeter is 51cm
The side lengths are x, x+2, and x+4
To find perimeter, we add all the side lengths.
Therefore, the equation we would use is the following:
x + x+2 + x+ 4 = 51
Then we solve for x
3x + 6= 51
Subtract 6 on both sides
3x = 45
divide by 3
x=15
Now, x is the smallest side, and we are trying to find the longest side,
So we plug in x for the longest length:
(15) + 4= 19
19cm is the longest side of the triangle.
