Question

in the adjoining figure ABCD is a trapezium in which parallel sides are AB=78 and DC=52 cm and the non parallel sides are BC = 30 cm and AD = 28 cm find the area of the trapezium

Answer 1

Draw DE perp. to AB we get triangle ADE ,AE = AB - DC
AE= 78-52
AE =26


a right angles triangle ADE right angles at E
By using P. G. T
AD*2 =AE*2 + ED* 2
28*2 =26*2+ED*2
784 = 666 + ED*2
786 - 666 = ED *2
120= ED*2
√120 = ED
√4*30 =ED
2√30 =ED
NOW,
AREA OF TRAPEZIUM =
A. =a + b /2 * h
= 52 * 78 /2 * 2 √30
= 4056 /2 *2√30
= 2028 *2√ 30
4056√30




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Answer 2

Draw DE perp. to AB we get triangle ADE ,AE = AB - DC

AE= 78-52

AE =26

a right angles triangle ADE right angles at E

By using P. G. T

AD*2 =AE*2 + ED* 2

28*2 =26*2+ED*2

784 = 666 + ED*2

786 - 666 = ED *2

120= ED*2

√120 = ED

√4*30 =ED

2√30 =ED

NOW,

AREA OF TRAPEZIUM =

A. =a + b /2 * h

= 52 * 78 /2 * 2 √30

= 4056 /2 *2√30

= 2028 *2√ 30

4056√30