Question

in the figure , AB and DC are parallel sides of a trapezium ABCD and angle ADC =90° GIVEN AB =15cm,cd=40 cm and diagonal AC =41 cm,calculate the area of trapezium ABCD

Answer 1

In the trapezium ABCD,

Parallel sides have lengths=15,40

Also if angleADC is 90

Then AD is the perpendicular distance between the two parallel sides AB and DC

Area of trapezium =1/2*(a+b)h

Where a and b are the parallel sides

Also,in right angled triangle ADC,

sq AD+sq DC=sq AC

sq AD=(41*41)-(40*40)=81

AD=✓81=9

Putting this value in h of trapezium ABCD

Area=1/2(40+15)*9=247.5