Question

The three angles of a quadrilateral are equal. If the measure of the fourth angle is
120", what is the measure of each of the equal angles ?​

Answer 1

Given thαt,

• The three angles of a quadrilateral are equal.
• The measure of fourth angle is 120°.

◾️We need to find the measure of each of the equal angles.

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To do so,

Let's assume that each of the three angles be x.

And as we know that $\large{\boxed{\sf{\orange{Angle\:Sum\:Property_{(Quadrilateral)} = 360°}}}}$

According to the question,

$\longrightarrow{\sf{x+x+x+120=360}}$

• Add the variables.

$\longrightarrow{\sf{3x+120=360}}$

$\longrightarrow{\sf{3x=360-120}}$

• Transpose 120 to R.H.S.

$\longrightarrow{\sf{3x=240}}$

• Transpose 3 to R.H.S.

$\longrightarrow{\sf{x=\dfrac{240}{3}}}$

$\large\longrightarrow{\boxed{\sf{\orange{x=80°}}}}$

Therefore, the measure of each of the equal angles is 80°.

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