a) Let a < b and c < d be real numbers. Sketch a graph of the

Question:

a) Let a < b and c < d be real numbers. Sketch a graph of the rectangle
[a, b] × [c, d] := [(x, y) : x ∈ [a, b], y ∈ [c, d]},
and decide whether this set is compact or connected. Explain your answers.
b) Sketch a graph of set
B1(-2, 0) U B1(2, 0) U {(x, 0): -1 < x < 1},
and decide whether this set is compact or connected. Explain your answers.