Let the proportion be 3x, 4x and 5x .
We know that sum of all angles of a triangle measures 180°.
So, keeping the values equals to 180°.
⇒ 3x + 4x + 5x = 180°
⇒ 12x = 180°
⇒ x = 180°/12
⇒ x = 15°
Now, finding the each angle measure.
⇒ 3x = 3 × 15 = 45°
⇒ 4x = 4 × 15 = 60°
⇒ 5x = 5 × 15 = 75°
Hence, the measure of each angle is 45°, 60° and 75° respectively.
❒ Required Solution:
So, Let's assume the angles as 3x, 4x and 5x.
❍ According to the question :
[tex]\\ \tt \implies \: 3 x+ 4x + 5x = 180{}^{ \circ} \\[/tex]
[tex]\\ \tt \implies \: 12 x = 180{}^{ \circ} \\[/tex]
[tex]\\ \tt \implies \: x = \frac{180{}^{ \circ} }{12} \\ [/tex]
[tex]\\ \implies \tt \: x = 15{}^{ \circ} [/tex]
Hence,
[tex]\: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \circ \: \: \: \: \tt \:1st \: \: \: angle \: \: \: \: \: = 3x=3 \times 15=45{}^{\circ} \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \\ \\ \circ \: \tt \:2nd \: \: \: angle \: \: \: \: \: = 4x=4\times 15=60{}^{\circ} \: \: \: \: \: \\ \\ \circ \: \: \: \: \tt \:3rd \: \: \: angle \: \: \: \: \: =5 x=5\times 15=75 {}^{\circ} \: \: \\ \\[/tex]
❒ V E R I F I C A T I O N :
Sum of the angles of the triangle = 180°
[tex]\\ \tt \implies \: 3 x + 4x + 5x = 180{}^{ \circ} [/tex]
[tex]\\ \tt \implies \: 45 {}^{ \circ} + 60{}^{ \circ} + 75{}^{ \circ}= 180{}^{ \circ} [/tex]
[tex]\\ \tt \implies \: 180{}^{ \circ} = 180{}^{ \circ} [/tex]
[tex]\\ {\quad { \quad{ \quad{ \textbf{ \textsf{L.H.S = R.H.S}}}}}}[/tex]
