Question

If two measures of two angles of a triangle is 3o and 40° then find measure of third angle.​

Answer 1

Answer:

sum of all angles of a triangle = 180°

30°+40° + 3rd side = 180°

70° +3rd side = 180°

3rd side = 180°- 70°

3rd side= 110°

Answer 2

★ Solution :-

In the question, we're given with the measurements of two of the angles of a triangle. We aren't given with the measurement of the other angle. We are asked to find it. As we know that, if we're given to solve the triangle's angle related problems, we should use the concept of the angle sum property.

Each figures has it's own angle sum property. The triangle also has one. We use this method to find the measurement of the unknown angles of the triangle. So, let's find the value of the third angle.

Measurement of third angle :-

$\sf \leadsto {Angle \: sum \: property}_{(Triangle)} = {180}^{\circ}$

$\sf \leadsto {30}^{\circ} + {40}^{\circ} + \angle{3} = {180}^{\circ}$

$\sf \leadsto {70}^{\circ} + \angle{3} = {180}^{\circ}$

$\sf \leadsto \angle{3} = 180 - 70$

$\sf \leadsto \angle{3} = {110}^{\circ}$

Therefore, the value of the third angle is 110°.

$\:$

Now, we can check that our answer is correct or not. So, let's check now.

$\sf \leadsto \angle{1} + \angle{2} + \angle{3} = {180}^{\circ}$

$\sf \leadsto {30}^{\circ} + {40}^{\circ} + {110}^{\circ} = {180}^{\circ}$

$\sf \leadsto {70}^{\circ} + {110}^{\circ} = {180}^{\circ}$

$\sf \leadsto {180}^{\circ} = {180}^{\circ}$

Thus, we can conclude that our answer is correct.