Write an equation of a circle in general Expanded form: x^2 + y^2 -8x + 16y + 55 = 0

Can someone me with these two circle theorem questions asap?

Find the missing variable for a parallelogram: a = latex: 32in^2 32 i n 2 h = b = 6.3 in (1in=2.54cm)

The base of a pyramid is a square with 5 lines of 5cm the slant height of each lateral face of the pyramid is 6 cm what is the surface area of the pyramid