In Fig. 2.39.

(a) What is AE + EC?

(b) What is AC – EC?

(c) What is BD – BE?

(d) What is BD – DE?

In Fig. 2.37,

(a) name any four angles that appear to be acute angles.

(b) name any two angles that appear to be obtuse angles.

In Fig. 2.38,

(a) is AC + CB = AB?

(b) is AB + AC = CB?

(c) is AB + BC = CA?

Using the information given, name the right angles in each part of Fig. 2.40:

(a) BA ⊥BD

(b) RT ⊥ST

(c) AC ⊥BD

(d) RS ⊥RW

(e) AC ⊥BD

(f) AE ⊥CE

(g) AC ⊥CD

(h) OP ⊥AB

Fig. 2.40

What conclusion can be drawn from each part of Fig. 2.41, if

(a) DB is the bisector of ∠ADC?

(b) BD bisects ∠ABC?

(c) DC is the bisector of ∠ADB, CA ⊥ DA and CB ⊥ DB?