Question

Find the values of x from the adjoining figure​

Answer 1

39°

Explanation:

In ∆ACDHere AC = AD

Their base angles are equal.

<ACD = <ADC = 78°

Also in ∆ ABC, <C is exterior angle.

So ext angle = Sum of interrior opp. <s

=> 78 = x + <B

But <CAB = < CBA = x[ AC = BC]

<B = x

so 78 =x+x => 2x = 78

=> x = 39°

Answer 2

Hello!

Answer:

39°

Explanation:

• An isosceles triangle is a triangle that has two sides of equal length.

AC = AD so the triangle ACD is isoceles.

BC = AC so the triangle ABC is isoceles.

• The base angles of an isosceles triangle are equal.

ADC = 78°

So the angle ACD = 78°

• A straight angle is equal to 180°.

BCD is a straight angle, BCD = 180°.

So the angle BCA = BCD - ACD = 180° - 78° = 102°

• The sum of the angles of a triangle is equal to 180°.

The triangle ABC is isosceles.

So the angles of the base = (180° - 102°)/2 = 39°

So the angles BAC and CBA = 39°

So the value of x = 39°.