Name the following angles of Fig. 2.29, using three letters:
(a) ∠1
(b) ∠2
(c) ∠3
(d) ∠1 + ∠2
(e) ∠2 + ∠3
(f) ∠1 + ∠2 + ∠3
(g) ∠CBA – ∠1
(a) ∠ 1 = ∠ CBD
(b) ∠ 2= ∠ DBE
(c) ∠ 3 = ∠ EBA
(d) ∠ 1 +∠ 2 = ∠ CBD + ∠ DBE
= ∠ CBE
(e) ∠ 2 + ∠ 3 = ∠ DBE + ∠ EBA
= ∠ DBA
(f) ∠ 1 +∠ 2 + ∠ 3 = ∠ CBD + ∠ DBE + ∠ EBA
= ∠ CBA or ∠ ABC
(g) ∠ CBA - ∠ 1 = ∠ CBA - ∠ CBD
= ∠ DBA or ∠ ABD
47