Question

Find the area of a trapezium whose parallel sides are 77cm 60cm and other two sides are 25cm and 26cm?

Answer 1

Draw a line BC parallel to AD 

Draw a perpendicular line BE on DF

ABCD is a parallelogram.

BC=AD=25cm

CD=AB=60cm

CF=77-CD=17cm

For Δ BCF

perimeter of triangle=(25+26+17)/2

=68/2=34

By Heron's Formula of triangle=√s(s-a)(s-b)(s-c)

=√34(34-25)(34-26)(34-17)

=204cm²

Now area of ΔBCF=1/2xbase x height

=1/2 BExCF204cm²

=1/2x BEx17BE

=408/17

=24cm

Area of Trapezium =1/2(AB+DF)xBE

=1/2(60+77)x24

=1644cm²

Answer 2

Answer:

area ABEC

s=  

2

25+26+17

​

=34

area ΔBEC=  

34×9×8×17

​

 

=17×3×2×2=204cm  

2

 

area ΔBEC=  

2

1

​

×17×h=204

h=  

17

204×2

​

=24

area trap. ABCD =  

2

1

​

(60+77)×24=137×12=1644cm  

2

Step-by-step explanation: