How is every one doing

Given that ot =5, xt=12, and ox= 13 is xy tangent to circle o at t? explain.

We just started the introduction into circles and i have no idea how to do this.

The area of a rectangle is 10 cm^2. one side of the rectangle is x cm. express the perimeter of the rectangle in terms of x and show that this rectangle cannot have a perimeter of 12 cm. the perimeter of the rectangle in terms of x is __ cm