how are tendons and blood related

A number of arteries may be responsible for contributing to the blood supply of a tendon. For instance, six arteries supply blood to the rotator cuff tendons.

They both exist in the human body. Other animals too. They both come out of bones.

well they live in the same house so I thought...

im going to stay here so i get the answer too

Although everything in the body is related, tendons and blood are not very related per se. Blood is very important in many functions in the body such as carrying oxygen supplying, white blood cells, and carrying nutrients from the digestive tract to storage sites.
Tendons are pulleys for our muscles and have very little blood flow compared to muscle. Tendons are made of collagen fibers.