Question

if two angles of a triangle are 30 °and 40°respectively then measure the third angle​

Answer 1

Given:

• Two angles of a triangle are 30 °and 40° respectively.

To Find:

• Measure of third angle

Solution:

Here in the question we are given two angles of the triangle. Let the third angle of traingle be x. We know that sum of all angles of triangle is 180°. Then, Using angle sum property we will find the Third angle of the triangle.

Let the third angle be x°

According to the Question :

⟹ Angle Sum Property of Triangle = 180°

⟹ 30° + 40° + x = 180

⟹ 70° + x = 180°

⟹ x = 180° - 70°

⟹ x = 110°

Verification:

⟹ Angle Sum Property of Triangle = 180°

⟹ 30° + 40° + 110° = 180°

⟹ 70° + 110° = 180°

⟹ 180° = 180°

Hence, Verified

Therefore :

• Third angle of Triangle is 110°.

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Answer 2

❒ Required Solution:

• It is given that the two angles of the triangle are 30° and 40° respectively. And we are here to find the third angles with the help of the angle sum property (Sum of the angles of a triangle = 180°). So, using this property we can find the third angle.

So, Let's assume the third angle as x.

❍ According to the question :

$\\ \tt \implies \: 30 {}^{ \circ} + 40{}^{ \circ} + x = 180{}^{ \circ}$

$\\ \tt \implies \: 70{}^{ \circ} + x = 180{}^{ \circ}$

$\\ \tt \implies \: x = 180{}^{ \circ} - 70{}^{ \circ}$

$\\ \implies \tt \: x = 110{}^{ \circ}$

❒ V E R I F I C A T I O N :

Sum of the angles of the triangle = 180°

$\\ \tt \implies \: 30 {}^{ \circ} + 40{}^{ \circ} + x = 180{}^{ \circ}$

$\\ \tt \implies \: 30 {}^{ \circ} + 40{}^{ \circ} + 110{}^{ \circ}= 180{}^{ \circ}$

$\\ \tt \implies \: 180{}^{ \circ} = 180{}^{ \circ}$

$\\ {\quad { \quad{ \quad{ \textbf{ \textsf{L.H.S = R.H.S}}}}}}$