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Question
The parallel sides of a trapezium are in ratio 3: 4. If the distance between the parallel sides is 9 dm and its area is 126 dm2; find the lengths of its parallel sides.
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Solution
Let parallel sides of trapezium be
a = 3x
b = 4x
Distance between parallel sides, h = 9 dm
area of trapezium = 126 dm2
`1/2 (a + b) xx h = 126`
`1/2 (3x + 4x) xx 9 = 126`
`7x xx 9 = 126 xx 2`
`x = (126 xx 2)/(7 xx 9)`
x = 4
a = 3x = 3 × 4 = 12 dm
b = 4x = 4 × 4 = 16 dm
12 dm , 16 dm
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