Since we know that the hypotenuse is 11 and this is a 30 - 60 - 90 right triangle we can use 11 to find the other sides.
The hypotenuse is 2s, s is the 30 side length.
So s = 11 / 2 = 5.5
The 60 side is s * square root of 3.
5.5 * square root of 3 = about 9.5.
Now that we know all three sides we can add them together to get the perimeter.
11 + 5.5 + 9.5 = 26
:)))