Given that in ΔABC, side AB is produced to D So that BD = BC and ∠B = 60° and ∠A = 70°,
We have to prove that
(i) AD > CD
(ii) AD > AC
First join C and D
Now, in ΔABC
Sum of angles in a triangle=180°
[ Angles opposite to equal sides are equal]
Now,
Sum of angles in a triangle=180°
[∵ Side opposite to greater angle is longer and smaller angle is smaller]
[∵ Side opposite to greater angle is longer and smaller angle is smaller]