Question

three angles of a quadrilateral are 100 degree, 90degree and 110degree what is the fourth angle
options are:
a) 30degree
b)120 degree
c)160degree
d)60 degree​

Answer 1

Answer :-

• 4th Angle = 60°

Explanation :-

Given :

• 1st Angle = 100°
• 2nd Angle = 90°
• 3rd Angle = 110°

To Find :

• 4th Angle.

Solution :

Let the 4th Angle be x.

We know that,

Sum of all angles in Quad. = 360°

So,

➙ 100° + 90° + 110° + x° = 360°

➙ 190° + 110° + x° = 360°

➙ 300° + x° = 360°

➙ x° = 360 - 300.

➙ x° = 60°

Therefore, 4th Angle = 60°

Verification :

Sum of all angles in Quad. = 360°

➙ 100° + 90° + 110° + x° = 360°

➙ 190° + 110° + 60° = 360°

➙ 300° + 60° = 360°

➙ 360° = 360°

LHS = RHS.

Hence, Verified.

Answer 2

Hence, the fourth angle of a quadrilateral is 60°.

So, option (d) 60 degree is correct.❤️~