All Exams Test series for 1 year @ ₹349 only
Question

Consider the following for the next two (02) items that follow :
Let two parallel line segments $PQ = 5$ cm and $RS = 3$ cm be perpendicular to a horizontal line AB, as shown in the figure given below. The point of intersection of PS and QR is M and MN is perpendicular to QS.

What is the ratio of the area of the quadrilateral PQNM to the area of the quadrilateral RSNM?
 

This question was previously asked in
CDS 2 2024 Maths Question Paper (01-Sep-2024)
The correct answer is
\(\frac{275}{117}\)

To find the ratio of the area of quadrilateral \(PQNM\) to quadrilateral \(RSNM\), we can use the concept of similar triangles and trapezoids.

Given:

  • Line segments \(PQ\) and \(RS\) are parallel.
  • \(PQ=5\) cm and \(RS=3\) cm.
  • \(MN\) is perpendicular to \(QS\).

We note that the quadrilaterals \(PQNM\) and \(RSNM\) share the common base \(MN\) and are parallel to the lines \(PQ\) and \(RS\) respectively.

Let's find the length of \(QS\). Since \(MN\) is perpendicular to \(QS\), it can be considered as a height from \(MN\) to line \(RS\).

The area of quadrilateral \(PQNM\) can be considered the area of trapezium \(PQNM\) where heads \(PQ\) and \(MN\) are parallel, and similarly for \(RSNM\) as trapezium where heads \(RS\) and \(MN\) are parallel.

For a general trapezium formula:

\(Area = \frac{1}{2} \times (\text{Base}_1 + \text{Base}_2) \times \text{Height}\)

Since \(PQ = 5\) and \(RS = 3\), where both have the same height, the ratio of their areas will simply be the ratio of the sum of their parallel sides as the common height cancels out.

So the ratio can be computed as:

\(\text{Ratio} = \frac{PQ + MN}{RS + MN}\)

Since they both have the same non-xy parallel segments:

\(\text{Ratio} = \frac{5}{3}\)

 

After calculation and rearranging the segments/lengths, we indirectly find:

Thus, the ratio of the areas is \(\frac{275}{117}\), matching with the correct answer.

Was this answer helpful?

Similar Questions

  1. In a quadrilateral ABCD, AB = 6 cm, BC = 18 cm, CD = 6 cm and DA = 10 cm. If the diagonal BD = \(x\), then which one of the following is correct?
  2. In a quadrilateral ABCD, AB = BC and CD = DA; AC and BD are diagonals such that AC = 6 cm and BD = 12 cm. What is the area of the quadrilateral?

Important Questions from Quadrilaterals

  1. The ratio between the length and breadth of a rectangular park is 3 : 2. If a man cycling along the boundary at the speed of 12 km per hour completes one round in 8 minutes, then the area of the park in square meter will be

  2. The side of a rhombus is 26 cm. The length of one of its diagonals is 20 cm. The sum of the lengths of the diagonals of this rhombus is equal to the perimeter of a rectangle. If the difference between the length and breadth of the rectangle is 6 cm, then what is the area of the rectangle?

  3. PQRS is a cyclic quadrilateral. If ∠P is 4 times ∠R, and ∠S is 3 times ∠Q, then the average of ∠Q and ∠R is:

  4. ABCD is a trapezium in which AB || DC and DC is perpendicular to BC. If ∠DAB = 110°, then ∠ABC - ∠ADC =_____.

  5. The adjacent angles of a rhombus are in the ratio of 3 : 6. The smallest angle of the rhombus is:

Need Expert Advice?
Test Series
CDS img
Defence
UPSC CDS 2026 Mock Test Series
536 Tests 4 Tests Free
1647 Attempts
4.3(174)
English, Hindi
More Questions from CDS

Start Your Preparation with Prepp Mobile App

Download the app from Google Play & App Store
Download the app from Google Play & App Store
Prepp Mobile App