Advertisements
Advertisements
Question
In the given figure, if ∠BAC = 60° and ∠BCA = 20°, find ∠ADC.

Advertisements
Solution
It is given that, `angle BAC = 60°` and `angle BCA = 20°`

We have to find the `angle ADC `
In given Δ ABC we have
`angle ABC + angle BCA + angle BAC `= 180° \[ \left( \text{ Angle sum property } \right)\]
\[ \Rightarrow \angle ABC = 180° - \left( 60° + 20° \right) = 100° \]
In cyclic quadrilateral ABCD we have
`angle B + angleD = 180°` (Sum of pair of opposite angles of a cyclic quadilateral is 180º)
Then,
`angle D = 180° - 100° `
`angle D = 80° `
Hence `angle ADC = 80°`
APPEARS IN
RELATED QUESTIONS
ABC is a right triangle, right angled at B. A circle is inscribed in it. The lengths of the two sides containing the right angle are 6 cm and 8 cm. Find the radius of the incircle.
A chord of a circle of radius 14 cm subtends an angle of 120° at the centre. Find the area of the corresponding minor segment of the circle. `[User pi22/7 and sqrt3=1.73]`
In the given figure, if ∠ABC = 45°, then ∠AOC =
In the given figure, O is the centre of the circle and ∠BDC = 42°. The measure of ∠ACB is

From an external point P , tangents PA = PB are drawn to a circle with centre O . If \[\angle PAB = {50}^o\] , then find \[\angle AOB\]
If all the sides of a parallelogram touch a circle, show that the parallelogram is a rhombus.
In the given figure, O is the centre of a circle, chord PQ ≅ chord RS If ∠ POR = 70° and (arc RS) = 80°, find –
(1) m(arc PR)
(2) m(arc QS)
(3) m(arc QSR)


In the above figure, seg AB is a diameter of a circle with centre P. C is any point on the circle. seg CE ⊥ seg AB. Prove that CE is the geometric mean of AE and EB. Write the proof with the help of the following steps:
a. Draw ray CE. It intersects the circle at D.
b. Show that CE = ED.
c. Write the result using the theorem of the intersection of chords inside a circle. d. Using CE = ED, complete the proof.
Draw a circle of radius 4.8 cm and mark its center as P.
(i) Draw radii PA and PB such that ∠APB = 45°.
(ii) Shade the major sector of the circle
From a point P which is at a distance of 13 cm from the centre O of a circle of radius 5 cm, the pair of tangents PQ and PR to the circle are drawn. Then the area of the quadrilateral PQOR is ______
