##### Find the value of the unknown x in the following diagrams:

(i) In the above question, we have

1st interior angle = x, 2nd interior angle = 50o and 3rd interior angle = 60o

We have to find out the value of x

Thus,

x + 50o + 60o = 180o (angle sum property of triangle)

x + 110o = 180o

x = 180o – 110o

x = 70o

Hence, the value of x is 70o

(ii) In the above question, we have

1st interior angle = x, 2nd interior angle = 90o and 3rd interior angle = 30o

We have to find out the value of x

Thus,

x + 90o + 30o = 180o (angle sum property of triangle)

x + 120o = 180o

x = 180o – 120o

x = 60o

Hence, the value of x is 60o

(iii) In the above question, we have

1st interior angle = x, 2nd interior angle = 30o and 3rd interior angle = 110o

We have to find out the value of x

Thus,

x + 30o + 110o = 180o (angle sum property of triangle)

x + 140o = 180o

x = 180o – 140o

x = 40o

Hence, the value of x is 40o

(iv) In the above question, we have

1st interior angle = 50o, 2nd interior angle = xand 3rd interior angle = x

We have to find out the value of x

Thus,

50o + x + x = 180o (angle sum property of triangle)

2x + 50o = 180o

2x = 180o – 50o

2x = 130o

x =

x = 65o

Hence, the value of x is 65o

(v) In the above question, we have

1st interior angle = x, 2nd interior angle = x and 3rd interior angle = x

We have to find out the value of x

And,

x + x + x = 180o (angle sum property of triangle)

3x = 180o

x =

x = 60o

Hence, the value of x is 60o

(vi) In the above question, we have

1st interior angle = x, 2nd interior angle = 2x and 3rd interior angle = 90o

We have to find out the value of x

Thus,

x + 2x + 90o = 180o (angle sum property of triangle)

3x + 90o = 180o

3x = 180o – 90o

3x = 90o

x =

x = 30o

Hence, the value of x is 30o

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