Sketch the points $ (1, 5, 3) $, $ (0, 2, -3) $, $ (-3, 0, 2) $, and $ (2, -2, -1) $ on a single set of coordinate axes.

Describe and sketch the surface in $ \mathbb{R}^3 $ represented by the equation $ x + y = 2 $.

Describe and sketch the surface $ \mathbb{R}^3 $ represented by the equation $ x^2 + z^2 = 9 $.

Find the lengths of the sides of the triangle $ PQR $. Is it a right triangle? Is it an isosceles triangle?

$ P (3, -2, -3) $ , $ Q (7, 0, 1) $ , $ R (1, 2, 1) $

$ P (2, -1, 0) $ , $ Q (4, 1, 1) $ , $ R (4, -5, 4) $

Find an equation of the sphere with center $ (-3, 2, 5) $ and radius 4. What is the intersection of this sphere with the $ yz $-plane?