Question

find ACis greater thanCD

Answer 1

AB = AC

=> <ABC = <ACB [ angles opposite to equal sides are equal]

=> <ACB = 70°

______________

<ACD = 180 - 70°

=> <ACD = 110°

Now,

In Triangle ACD

By angle sum property of triangle,

<ACD + <CAD + <ADC = 180°

=> 110 + <CAD + 40° = 180°

=> <CAD + 150 = 180

=> <CAD = 30°

Now,

We know that,

Side opposite to greater angle is greater than the side opposite to smaller angle.

So,

AC > CD

=> AB > CD

Hence Proved......