Question

the area of a Trapezium is 210 CM square and its height is 40 cm if one of the parallel side is double that of the Other find the two parallel side

Answer 1

Answer :

Given Area of Trapezium = 210 cm sq.

Given height = 40 cm

It is given that one of the parallel sides is double of the other parallel side.

So let one parallel side be x

Then other parallel side will be 2 × x = 2x

$as \: we \: know \: that \: area \: of \: trapezium \: = \: \frac{1}{2} (sum \: of \: parallel \: sides)h \\ \\ therefore \\ \\ 210 = \frac{1}{2} (x + 2x)40 \\ \\ or \: \: \frac{1}{2} (x + 2x)40 = 210 \\ \\ \frac{1}{2} (3x)40 = 210 \\ \\ 3x \times 40 = 210 \times 2 \\ \\ 3x \times 40 = 420 \\ \\ 3x = \frac{420}{40} \\ \\ 3x = \frac{21}{2} \\ \\ x = \frac{21}{2} \div 3 \\ \\ x = 3.5$

x = 3.5

Therefore 1 side = 3.5 cm

and other side = 2(3.5) = 7 cm


VERIFICATION ---

Put the value of x, to find whether the answer is right or wrong

L.H.S =

1/2( 3.5 + 7) 40

=> 1/2 × 10.5 × 40

=> 21/2 × 40

=> 210 = R.H.S

Since, L.H.S = R.H.S
Therefore, the value of x is x correct.