Question

The sum of the angles of a triangle 180 * . if the three angles are (2x+15)* , 85* and (x+20)* , the value of x is. This is a degree​

Answer 1

Explanation:

2x +15 + 85 + x+20 =180

3x+120=180

3x=60

x=20

Answer 2

$\;\;\underline{\textbf{\textsf{ Given:-}}}$

• 1st angle = 180°

• 2nd angle = ( 2x + 15 )°

• 3rd angle = ( x + 20 )°

$\;\;\underline{\textbf{\textsf{ To Find:-}}}$

• Value of x

$\;\;\underline{\textbf{\textsf{ Solution -}}}$

We know that,

The sum of all the 3 interior angles of a triangle is 180° .

For any ΔABC :-

$\small\dag \: { \boxed{ \sf{\purple{\angle A + \angle B + \angle C = {180}^{ \circ}}}}}$

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$\bf\underline{\green{\:\:\:\:\:\:\:\:A.T.Q:-\:\:\:\:\:\:\:}}$

$\dashrightarrow \sf \: \: \: (2x + 15) + 85 + (x + 20) = 180$

$\dashrightarrow \sf \: \: \: 3x + 120 = 180$

$\dashrightarrow \sf \: \: \: 3x = 180 - 120$

$\dashrightarrow \sf \: \: \: 3x = 60$

$\dashrightarrow \sf \: \: \: x = \dfrac{60}{3}$

$\dashrightarrow \sf \: \: \: { \underline{ \boxed{ \sf{ \purple{x = {20}^{ \circ}}}}}}$

ㅤ$\;\;\underline{\textbf{\textsf{ Therefore -}}}$

$\underline{\textsf{ Value of x is \textbf{20°}}}.$

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