The triangle PQR has sides of length 8, 11, and y - Junior Cycle Mathematics - Question 12(a) - 2015

For triangle PQR to be an isosceles triangle, at least two sides must be of equal length. This can occur in two scenarios:

1. If $y = 8$, then the sides of the triangle are 8, 8, and 11.
2. If $y = 11$, then the sides of the triangle are 11, 11, and 8.

Thus, one valid value for $y$ is:

$y = 8$

or

$y = 11$.