Question

From the given figure, the value of x is ______.

Options

• 75°

• 90°

• 120°

• 60°

Answer 1

From the given figure, the value of x is 120°.

Explanation:

In ΔABC, ∠CAB + ∠ABC + ∠BCA = 180°  ...[Angle sum property of a triangle]

⇒ 25° + 35° + ∠BCA = 180°

⇒ ∠BCA = 180° – 60°

⇒ ∠BCA = 120°

Also, ∠BCA is an exterior angle

∴ ∠BCA = ∠D + y

⇒ y = ∠BCA – ∠D = 120° – 60°  ...[∵ ∠D = 60°, given]

⇒ y = 60°

Now, ∠x and ∠y from a linear pair

∴ x + y = 180°

⇒ x + 60° = 180°

⇒ x = 180° – 60° = 120°