Question

please answer eighth question

Answer 1

this is your answer
ok...

Answer 2

Answer:

∠A + ∠B + ∠C = ∠ADC

Step-by-step explanation:

(i) In ΔDAC,

⇒ ∠ADC + ∠DCA + ∠DAC = 180°

⇒ ∠DCA + ∠DAC = 180° - ∠ADC

(ii) In ΔABC,

⇒ ∠BAC + ∠ACB + ∠CBA = 180°

⇒ ∠BAD + ∠DAC + ∠DCA + ∠DCB + ∠CBA = 180°

⇒ ∠BAD + ∠DCB + ∠CBA + (∠DCA + ∠DAC) = 180°

⇒ ∠BAD + ∠DCB + ∠CBA + 180° - ∠ADC = 180°

⇒ ∠A + ∠C + ∠B + 180° - ∠ADC = 180°

⇒ ∠A + ∠B + ∠C = 180° - 180° + ∠ADC

⇒ ∠A + ∠B + ∠C = ∠ADC.

Hope it helps!