Question

In triangle A B C,AB=AC and angleA =40°.Find x and y.​

Answer 1

Answer:

x = 110° and y = 110°

Step-by-step explanation:

In ∆ABC

→ angle B = angle C

(angles opposite to equal sides are equal)

→ A+B+C = 180° (ASPT)

40°+2B = 180° (B=C)

2B = 180°-40°

2B = 140°

B = 140°/2

B = 70° , C = 70°

B+x = 180° (LPA)

70°+x = 180°

x = 180°-70°

x = 110°

Similarly,

C+y = 180°

70°+y = 180°

y = 180°-70°

y = 110°

Answer 2

Answer:

co- interior angles are supplementary

So,then...let angle 1

$40 + angle1 = 180 \\ angle1 = 180 - 40 \\ angle1 = 140$

Now ,again.. co-interior angles are supplementary....so, let a angle 2

$140 + angle2 = 180 \\ angle2 = 180 - 140 \\ angle2 = 40$

now, linear pair

$y + angle1 = 180 \\ y + 140 = 180 \\ y = 180 - 140 \\ y = 40$

Now, again linear pair

$x + angle1 = 180 \\ x + 40 = 180 \\ x = 180 - 40 \\ x = 140$

so, the value of x =140°

and the value of y =40°