KnowledgeBoat Logo
|

Mathematics

AB is diameter of the circle. PA is tangent and ∠AOC = 60°.

AB is diameter of the circle. PA is tangent and ∠AOC = 60°. Concise Mathematics Solutions ICSE Class 10.

Assertion(A): x + 30° = 90°.

Reason(R): PA is tangent

⇒ ∠BAP = 90°

∴ x + 30° = 90°

  1. A is true, R is false.

  2. A is false, R is true.

  3. Both A and R are true and R is correct reason for A.

  4. Both A and R are true and R is incorrect reason for A.

Circles

4 Likes

Answer

We know that,

The angle subtended by an arc of a circle at the center is double the angle subtended by it at any point on the remaining part of the circle.

∴ ∠AOC = 2 x ∠ABC

⇒ 60° = 2 x ∠ABC

⇒ ∠ABC = 60°2\dfrac{60°}{2} = 30°

The tangent at any point of a circle is perpendicular to the radius through the point of contact.

∴ AP ⊥ OA

⇒ ∠OAP = 90°

⇒ ∠OAP = ∠BAP = 90°

In ΔABP, according to angle sum property,

∴ ∠ABP + ∠APB + ∠BAP = 180°

⇒ 30° + x + 90° = 180°

⇒ 30° + x = 180° - 90°

⇒ 30° + x = 90°.

∴ Both A and R are true and R is correct reason for A.

Hence, option 3 is the correct option.

Answered By

2 Likes


Related Questions