A bisector BD is drawn in triangle ABC, angle A = 75 ° angle C = 35 ° 1.Prove that triangle ABC is isosceles

A bisector BD is drawn in triangle ABC, angle A = 75 ° angle C = 35 ° 1.Prove that triangle ABC is isosceles 2.Compare AD and DC.

Consider ΔABS. ∠В = 180 – ∠А – ∠С = 180 – 75 – 35 = 70 °. ∠DBC = 1/2 ∠ABS = 35 ° ⇒

∠DBC = ∠С, ΔВDC is isosceles, as required.

In ΔАВD ∠А there is more than ∠АВD, which means we can say with precision that the side ВD is larger than АD, ВD = DС⇒

DC is more than AD.