Mathematics
In the given figure, AB is the diameter of the circle, with center O, and AT is the tangent. Calculate the numerical value of x.

Circles
13 Likes
Answer
In △OBC,

OB = OC (Radius of same circle)
As, angles opposite to equal sides are equal.
∴ ∠OBC = ∠OCB
As, exterior angle is equal to the sum of two opposite interior angles.
∴ ∠COA = ∠OBC + ∠OCB
⇒ ∠COA = 2∠OBC
⇒ 2∠OBC = 64°
⇒ ∠OBC = 32°.
In △ABT,
∠BAT = 90° (∵ Tangent at any point of a circle and the radius through this point are perpendicular to each other.)
⇒ ∠BAT + ∠ABT + ∠ATB = 180° (By angle sum property of triangle)
⇒ 90° + 32° + x° = 180° [∵ ∠ABT and ∠OBC is the same angle]
⇒ x° + 122° = 180°
⇒ x° = 180° - 122°
⇒ x° = 58°.
Hence, x = 58°.
Answered By
6 Likes
Related Questions
In the figure, given below, O is the center of the circumcircle of triangle XYZ. Tangents at X and Y intersect at point T. Given ∠XTY = 80° and ∠XOZ = 140°, calculate the value of ∠ZXY.

In the given figure, AE and BC intersect each other at point D. If ∠CDE = 90°, AB = 5 cm, BD = 4 cm and CD = 9 cm, find AE.

In the given circle with centre O, angle ABC = 100°, ∠ACD = 40° and CT is a tangent to the circle at C. Find ∠ADC and ∠DCT.

In the figure given below, O is the center of the circle and SP is a tangent. If ∠SRT = 65°, find the values of x, y and z.
