Advertisements
Advertisements
Question
☐ PQRS is an isosceles trapezium l(PQ) = 7 cm. seg PM ⊥ seg SR, l(SM) = 3 cm, Distance between two parallel sides is 4 cm, find the area of ☐ PQRS.

Advertisements
Solution

Draw a perpendicular from Q to line MR. Where it meets the line MR, name it point N.
MN = PQ = 7 cm
In ΔPMS,
PM² + SM² = PS²
⇒ 4² + 3² = PS²
⇒ PS² = 16 + 9
⇒ PS² = 25
⇒ PS = 5cm
PQRS is an isosceles trapezium so, PS = QR = 5 cm
PM = QN = 4 cm
So, NR = SM = 3 cm
SR = SM + MN + NR
= 3 + 7 + 3
= 13 cm
Area of trapezium PQRS = `1/2 xx` (sum of parallel sides) × height
=`1/2 xx (7 + 13) xx 4`
= 40 cm²
RELATED QUESTIONS
Find the area, in square metres, of the trapezium whose bases and altitude is as under:
bases = 8 m and 60 dm, altitude = 40 dm
The area of a trapezium is 960 cm2. If the parallel sides are 34 cm and 46 cm, find the distance between them.
Top surface of a table is trapezium in shape. Find its area if its parallel sides are 1 m and 1.2 m and perpendicular distance between them is 0.8 m.
The cross-section of a canal is a trapezium in shape. If the canal is 10 m wide at the top 6 m wide at the bottom and the area of cross-section is 72 m2 determine its depth.
Find the area enclosed by each of the following figures [Fig. 20.49 (i)-(iii)] as the sum of the areas of a rectangle and a trapezium:
The following figure shows the cross-section ABCD of a swimming pool which is a trapezium in shape.

If the width DC, of the swimming pool, is 6.4 m, depth (AD) at the shallow end is 80 cm and depth (BC) at the deepest end is 2.4 m, find its area of the cross-section.
Find the missing values.
| Height 'h' | Parallel side 'a` | Parallel side 'b` | Area |
| 13 cm | 28 cm | 492 sq.cm |
The area of the trapezium, if the parallel sides are measuring 8 cm and 10 cm and the height 5 cm is
The table top is in the shape of a trapezium with measurements given in the figure. Find the cost of the glass used to cover the table at the rate of ₹ 6 per 10 sq.cm
The areas of two circles are in the ratio 49 : 64. Find the ratio of their circumferences.
