Question

Q4. In the given figure ABCD, find the value of x.​

Answer 1

Answer:

x = 140°

Step-by-step explanation:

∠BAD= 180 - 70 = 110° (Linear pair/Angle in a straight line)

∠ABC= 180 - 80 = 100° (Linear pair)

∠BCD= 180 - 70 = 100° (Linear pair)

∠CDA+ ∠BAD + ∠ABC + ∠BCD = 360° (Angle sum of a quadrilateral)

∴ ∠CDA + 110° + 100° + 110° = 360°

 ∠CDA + 320° = 360°

 ∠CDA = 360° - 320° = 40°

Now,  ∠CDA + ∠x = 180°

         ⇒ 40° + x = 180°

         ⇒ x = 180° - 40° = 140°

 ∴ x = 140°

    Hope it helps....