Question

in triangle ABC AB=AC the value of x is ​

Answer 1

Answer:

The value of X is 130°.

Step-by-step explanation:

In this triangle ABC ,

AB = AC ,

so, it means that this is an isosceles triangle, and in an isosceles triangle the base angles are always equal,

so angle ABC = angle ACB

Let both these angles be of y° ,

So, by angle sum property of triangle we get,

angle BAC + angle ABC + angle ACB = 180°

80° + y + y = 180°

80° + 2y = 180°

2y = 100°

y = 50°.

Now, angle X and angle ACB forms a linear pair which is equal to 180°

So, X + angle ACB = 180°

X + 50° = 180°

Therefore , X = 130°.

Answer 2

Given: AB= AC

Angle A = 80°

To find : value of x

Solution:

we know

AB = AC

(two sides are equal Means triangle is isoceles , so opposite angles to sides are also equal )

=> angle B = angle C

let angle B AND C = y

Using angle sum property : sum of all angles of triangle is 180°

= 80°+ y + y = 180 °

80° + 2y = 180 °

2y = 180 ° - 80 °

2y= 100°

y = 100° / 2

y = 50 °

angle A = ANGLE B= y =50°

Now we can see that :

angle C+ x = 180° ( straight line angle )

50° + x = 180°

x = 180°-50°

x = 130°

Answer : Value of x = 130°