The parallel sides of trapezium are 65 cm and 49 cm and each of the non parallel sides is 10 cm. Find the area of Trapezium.

Draw CF || AD, intersecting AB in F and CE BF.

CF || AD and AF || CD.

AFCD is a parallelogram.

AF = CD = 49 cm    (Opposite sides of parallelogram are equal)

AD = CF = 10 cm  (Opposite sides of parallelograms are equal)

BF = AB – AF = 65 cm – 49 cm = 16 cm

ΔBCF is an isosceles triangle.

EF = EB= 16/2 = 8 cm  (In an isosceles triangle, altitude from the vertex bisects the base)

In ΔCFE,

CE2 + FE2 = CF2

CE2 = CF2 – FE2 = (10 cm)2 – (8 cm)2 = 100 cm2 – 64 cm2 = 36 cm2

CE = 6 cm

Area of trapezium 

= ½ × (AB + CD) × CE

= ½ × (65 + 49) × 6

= ½ × 114 × 6

= 114 × 3

= 342 cm2

 

 

  • 11

1/2 X (65+49) 10

(65+49) X 5 M

114 X 5 M 

570m2

  • -1

The formula is

1/2 X (a+b) X h

so..........

1/2 X (65+49) 10

(65+49) X 5 M

114 X 5 M

570m2

  • 0
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