Question

3) If the two angles of a triangle are 30 'and 40', then measure the third angle.​

Answer 1

Step-by-step explanation:

❒ Required Solution:

It is given that the two angles if 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 if 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 :

\begin{gathered} \\ \tt \implies \: 30 {}^{ \circ} + 40{}^{ \circ} + x = 180{}^{ \circ} \\ \end{gathered}

⟹30

∘

+40

∘

+x=180

∘

\begin{gathered} \\ \tt \implies \: 70{}^{ \circ} + x = 180{}^{ \circ} \\ \end{gathered}

⟹70

∘

+x=180

∘

\begin{gathered} \\ \tt \implies \: x = 180{}^{ \circ} - 70{}^{ \circ} \\ \end{gathered}

⟹x=180

∘

−70

∘

\begin{gathered} \\ \implies \tt \: x = 110{}^{ \circ} \\ \end{gathered}

⟹x=110

∘

❒ V E R I F I C A T I O N :

Sum of the angles of the triangle = 180°

\begin{gathered}\\ \tt \implies \: 30 {}^{ \circ} + 40{}^{ \circ} + x = 180{}^{ \circ} \\ \end{gathered}

⟹30

∘

+40

∘

+x=180

∘

\begin{gathered} \\ \tt \implies \: 30 {}^{ \circ} + 40{}^{ \circ} + 110{}^{ \circ}= 180{}^{ \circ} \\ \end{gathered}

⟹30

∘

+40

∘

+110

∘

=180

∘

\begin{gathered}\\ \tt \implies \: 180{}^{ \circ} = 180{}^{ \circ} \\ \end{gathered}

⟹180

∘

=180

∘

\begin{gathered} \\ {\quad { \quad{ \quad{ \textbf{ \textsf{L.H.S = R.H.S}}}}}}\end{gathered}

L.H.S = R.H.S

Answer 2

Step-by-step explanation:

1. let the third angle be=x
2. given two angle of triangle =30' and 40'
3. therefore the total angle of triangle=180'
4. therefore 180=30and40=70
5. 5.therefore 180-70=110
6. therefore third angle=110