Question

Two angles of a polygon are right angles and the remaining are 120° each. Find the number of sides in it​

Answer 1

Answer is 5 it has 5 sides

Answer 2

Answer:

Let the number of sides= Number of interior angles.

$= (n - 2) \times 180 \degree \\ \\ = 180n - 360 \degree$

Sum of 2 right angles

$= 2 \times 90 \degree \\ \\ = 180 \degree$

So sum of other angles =180n-360°-180°

=180n-540

No. of vertices at which the angles are formed =n-2.

So each interior angle

$= \frac{180n - 540}{n - 2} = 120 \degree \\ \\ 180n - 540 = 120n - 240 \\ \\ = 180n - 120n = - 240 + 540 \\ \\ 60n = 300 \\ \\ \therefore \: n = \frac{300}{60} \\ \\ \frac{ \cancel{30} \: \: ^{5} \cancel0}{ \cancel6 \cancel0} \\ \\ \boxed{ \sf \blue{n = 5}}$

Hope it helps you from my side