Question

If measure of three angles of a triangle are 2x-10, x+20 and 3x+80, then the value of 'x ' is​

Answer 1

Sum of angle of the triangle = 180

2x-10 + x+20 + 3x+80 = 180

6x + 90 = 180

6x = 180-90

x = 15

Answer 2

Given:

• Measure of first angle = (2x-10)°
• Measure of second angle = (x+20)°
• Measure of third angle = (3x+80)°

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To find:

Value of x.

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Solution:

We know that the sum of all the three angles of a triangle is 180°. [By Angle Sum Property of triangle]

So, the equation formed is,

(2x-10)° + (x+20)° + (3x+80)° = 180°

2x-10 + x+20 + 3x+80 = 180°

2x+x+3x -10+20+80 = 180°

6x+90° = 180°

6x = 180°-90°

6x = 90°

$\sf x = \dfrac{90}{ 6}$

$\boxed {\bf {\pink {x=15 \degree}}}$

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Verification:

On substituting the value of x as 15° in the equation,

(2x-10)° + (x+20)° + (3x+80)° = 180°

(2×15-10)° + (15+20)° + (3×15+80)° = 180°

(30-10)° + 35° + (45+80)° = 180°

20° + 35° + 125° = 180°

180° = 180°

LHS = RHS

Hence Verified!

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Final answer:

Value of x is 15°.