Question

In ΔABC, AB = AC. Find x in each of the following.​

Answer 1

Answer:

a) in triangle ABC ,

B=C=x

A+B+C=180

50+x+x=180

50+2x=180

2x=180-50=130

x=130/2=65

b)in triangle ABC,

B=C due to AB=AC,

A+B+C=180

x+65+65=180

x+130=180

x=180-130=50

c)in triangle ABC,

B=C due to AB=AC,

A+B+C=180

40+2B=180

2B=180-40=140

B=C=70

ABD is outer angle so ,

ABD=A+C

x=40+70=110

Answer 2

Answer:

1. angle A = 50

B = C (isoceles triangle)

B = x

let C be y

By angle sum property:

50+x+y=180

x + y = 180- 50

x + y = 130

B = 130

C = 130

2. A = x

B = C (isoceles triangle)

B = C = 65

By angle sum property:

x + 65 + 65 = 180

x + 130 = 180

x = 180-130

x = 50

Therefore, A = 50.

3. A = 40

let B be x.

C be y.

B = C (isoceles triangle)

By angle sum property

40+x+y = 180

x+y = 180-40

x+y = 140

Therefore, B=x=140

C=y= 140

linear pair,

x+B=180

x+140=180

x=180-140

x=40.

Hope it's helpful