Question

How do we do this???

Answer 1

Area of trapezium = (DE + CF)CD/2
Perimeter of ABCF = 20
2(AB + BC)= 20
BC = 4
Now draw a perpendicular to CD from E
name it as EG
EG = 6
since EF = 3 so CG = 3
BC + CG + DG = 9
DG = 2
now since EDG is a right angled triangle
so EG^2 + DG^2 = ED^2
ED = 2√10
Area of trapezium = (2√10 + 6)5/2
= 5(3 + √10)

Answer 2

Area of trapezium = (DE + CF)CD/2

Perimeter of ABCF = 20

2(AB + BC)= 20

BC = 4

Now draw a perpendicular to CD from E

name it as EG

EG = 6

since EF = 3 so CG = 3

BC + CG + DG = 9

DG = 2

now since EDG is a right angled triangle

so EG^2 + DG^2 = ED^2

ED = 2√10

Area of trapezium = (2√10 + 6)5/2

= 5(3 + √10)

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