The side EF, FD and DE of a triangle DEF are produced in order forming three exterior angles DFP, EDQ and FER respectively. Prove that
∠DFP + ∠EDQ + ∠FER = 360°.
OR
Prove that the sum of the exterior angles of a triangl is 360°.
Given: AD and CE are the angle bisectors of ∠A and ∠C respectively. ∠ABC = 90°
To Determine: ∠AOC
Determination: In ∆ABC,
∠A + ∠B + ∠C = 180°
| Angles sum property of a triangle
⇒ ∠A + 90° + ∠C = 180°
⇒ ∠A + ∠C = 90° ...(1)
In ∆AOC,
∠OAC + ∠OCA + ∠AOC = 180°
| Angle sum property of a triangle