I really need help with the rest of this packet or else I won’t pass

I'm a polygon i have no parallel lines i am formed 3 line segments i have one right angle two of my angles are angles what am i

Me d is also an option but i couldn't get it in the picture

Which is an equivalent equation solved for r? the circumference of a circle can be found using the formula c = 2πr. r=cπ r=c(2π) r= c over 2π r= 2π over c