Selina solutions

Selina solutions

Grade 7

Triangles | Exercise 15(A)

Question 1

Q1) State if the triangles are possible with the following angles :

(i)\ \ 20^{\circ},70^{\circ}and\ 90^{\circ}

(ii)\ 40^{\circ},130^{\circ}\ and\ 20^{\circ}

(iii)\ 60^{\circ},60^{\circ}\ and\ 50^{\circ}

(iv)\ 125^{\circ},40^{\circ}and\ 15^{\circ}

Solution:

We know that the sum of three angles of a triangle is 180°, therefore

(i) Sum of 20°, 70° and 90°

= 20° + 70° + 90° = 180°

Since the sum is 180°, Hence it is possible.

(ii) Sum of 40°, 130° and 20°

= 40° + 130° + 20° = 190°

Since, the sum is not 180°, therefore it is not possible.

(iii) Sum of 60°, 60° and 50°

= 60° + 60° + 50° = 170°

Since the sum is not 180°, therefore it is not possible.

(iv) Sum of 125°, 40° and 15°

= 125° + 40° + 15° = 180°

Since the sum is 180°, therefore it is possible.

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subject-cta

Question 1

Q1) State if the triangles are possible with the following angles :

(i)\ \ 20^{\circ},70^{\circ}and\ 90^{\circ}

(ii)\ 40^{\circ},130^{\circ}\ and\ 20^{\circ}

(iii)\ 60^{\circ},60^{\circ}\ and\ 50^{\circ}

(iv)\ 125^{\circ},40^{\circ}and\ 15^{\circ}

Solution:

We know that the sum of three angles of a triangle is 180°, therefore

(i) Sum of 20°, 70° and 90°

= 20° + 70° + 90° = 180°

Since the sum is 180°, Hence it is possible.

(ii) Sum of 40°, 130° and 20°

= 40° + 130° + 20° = 190°

Since, the sum is not 180°, therefore it is not possible.

(iii) Sum of 60°, 60° and 50°

= 60° + 60° + 50° = 170°

Since the sum is not 180°, therefore it is not possible.

(iv) Sum of 125°, 40° and 15°

= 125° + 40° + 15° = 180°

Since the sum is 180°, therefore it is possible.

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Book a free class now

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subject-cta
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