For starters, all the interior angles inside a pentagon add up to 540. This number can be found for any polygon with the forumla (n-2)180. N stands for the number of sides and then you plug it into the equation. For instance, if we wanted to find it for a triangle, we would see that the triangle has three sides and plug it into the formula. (3-2)180 which equals 180. For the ptenagon we take the fact that it has five sides and add it into the equation. (5-2)180 which equals 540. So now that we know all the interior angles are supposed to add up to 540, we can find the value of Y. So let's start by finding what amount we already have.
T=110
A=150
D=120
O=90 (this is beacuse of the right angle square placed which equals 90 degrees)
All those angles add to 470 degrees. So to find the last angle, you would subtract our total of 470 from our interior angle total of 540.
