Question
In a quadrilateral PQRS, the bisectors of ∠R and ∠S intersects each other at point 'O'. Find the ∠Q if ∠P = 75o and ∠ROS = 95o.
Solution

In ΔROS;
We have, ∠ROS + ∠ORS + ∠OSR = 180o
Or, 95o + ∠ORS + ∠OSR = 180o
Or, ∠ORS + ∠OSR = 85o
Or, (∠R/2) + (∠S/2) = 85o {∠ORS = (∠R/2) and ∠OSR = (∠S/2) }
So, ∠R + ∠S = 170o
We know that sum of each angle of a quadrilateral is 360o.
So, ∠P + ∠Q + ∠R + ∠S = 360o
Or, 75o + ∠Q + 170O = 360o
Or, ∠Q = 360o - 245o
So, ∠Q = 115o
More Geometry Questions
- Find the area of the region enclosed by the curves : y = 0, x = |y| and y = |x - 2|.
- O and C are the respectively orthocentre and circumcentre of ∆PQR. The line PO is extended which intersect line QR at S. such that, ∠QCR = 140°, ∠PQS = 58°...
- In a rectangle, length : breadth = 4 : 3. What is the value of length : diagonal?
- Let two chords AB and AC of the larger circle touch the smaller circle having same centre at X and Y. Then XY = ?
- In the given figure, ABCD is a square of side 14 cm. E and F are mid points of sides AB and DC respectively. EPF is a semicircle whose diameter is EF. LMNO...
- If G is the centroid and AD, BE, CF are three medians of ∆ABC with area 72 cm 2 , then the area of ∆BDG is?
- AC and CE are the medians of triangle ABD and ACD respectively. If area of triangle ACE is 15 cm 2 , then find the area of triangle ABD.
- Question 8
- In a triangle, the three interior angles are in the ratio 3 : 4 : 5. What is the measure of the largest angle?
- What will be inradius of an equilateral triangle of side 4 cm?