StePS for construct DE so that DE equals TR plus PS?

first you are suppose to draw a long ray (longer than tr and ps together) than you are suppose to take your compass and put the sharp point on line segement tr on t and the pencil part on r, than take the compass off and put it on the ray you drew and with the measurment of the compass put the pointy part on d(first point of ray) and the pencil part to where it goes and draw a arc(small one). Then you put your pointy part line segment ps(p) and the pencil part on s. then take your compass off and put the pointy part on the arc and the pencil part to wear it goes and draw another arc. Label that arc with e. Then put an arrow sign at the end of the ray and there you are done..