Advertisements
Advertisements
Question
In the following figure, if ∠OAB = 40º, then ∠ACB is equal to ______.

Options
50º
40º
60º
70°
Advertisements
Solution
In the following figure, if ∠OAB = 40º, then ∠ACB is equal to 50º.
Explanation:

Given: ∠OAB = 40º
Now, in triangle OAB,
OA = OB ...[Radii of circle]
So, ∠OAB = ∠OBA = 40º ...[Angle opposite to equal sides are equal]
So, ∠AOB = 180º – (40º + 40º) = 100º
As we know that 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.
So, ∠ACB = `1/2` ∠AOB = `1/2 xx 100^circ` = 50º
APPEARS IN
RELATED QUESTIONS
n Fig. 2, PQ and PR are two tangents to a circle with centre O. If ∠QPR = 46°, then ∠QOR equals:

(A) 67°
(B) 134°
(C) 44°
(D) 46°
In the given figure, O is the centre of the circle and TP is the tangent to the circle from an external point T. If ∠PBT = 30°, prove that BA:AT = 2:1.

PQ is a chord of length 8 cm of a circle of radius 5 cm. The tangents at P and Q intersect at a point T. Find the lengths of TP and TQ.

In Fig. 1, the sides AB, BC and CA of a triangle ABC, touch a circle at P, Q and R respectively. If PA = 4 cm, BP = 3 cm and AC = 11 cm, then the length of BC (in cm) is ?

Use the figure given below to fill in the blank:
EF is a ______ of the circle.

Construct a triangle PQR with QR = 5.5 cm, ∠Q = 60° and angle R = 45°. Construct the circumcircle cif the triangle PQR.
In figure, chords AC and DE intersect at B. If ∠ABE = 108°, m(arc AE) = 95°, find m(arc DC).

If A, B, C and D are four points such that ∠BAC = 45° and ∠BDC = 45°, then A, B, C, D are concyclic.
Is every chord of a circle also a diameter?
Which statement correctly defines a chord?
