36°
Diagram NOT
accurately drawn
Work out the size of angle y.

The angles in a isosceles triangle add up to 180 degrees.
so 180 degrees take away 36 degrees = 144 degrees.
base angles in a isoceles triangle are equal so 144 divided by 2 = 72 degrees.
so to find out y you do 360 - 72 = 288 degrees
therefore y = 288degrees

Answer = 288

Method:
Angles in a triangle add up to 180
The triangle is isosceles so the two interior angles at the bottom will be the same
180-36=144
Because you have two angles at the bottom you need to divide by two so
144/2=72 - that is the interior angle
To find y, all you need to do now is
360-72 = 288 (because angles round a point add up to 360)
And you have your answer
Hope this helps!