Question

Q21. The parallel sides of a trapezium are in there ratio 3:5 and the distance between the parallel sides is 12 cm.
If the area of the trapezium is 240 cm2
. Find the length s of its parallel sides.

Answer 1

Answer:

15 cm & 25 cm

Step-by-step explanation:

Parallel sides = 3x & 5x

1/2 × (3x + 5x) × 12 = 240

8x = 40

x = 5

Parallel sides = 15 cm & 25 cm

Answer 2

Given :-

• Ratio of the parallel sides = 3:5

• Distance between parallel sides (height) = h = 12 cm

• Area of the trapezium = 240 cm²

To Find :-

• Length of its parallel sides.

Solution :-

Let the parallel sides of be 3x and 5x.

We know that,

$\bullet\:\:\underline{\boxed{\bf{Area \:of\:the\:trapezium =\dfrac{1}{2} \times h \times (Sum\:of\:parallel \:sides )} }}}$

So,

$:\implies\: \sf{240=\dfrac{1}{2}\times 12 \times (5x+3x) }$

$:\implies\: \sf{240= 6 \times (5x+3x) }$

$:\implies\: \sf{240= 6 \times 8x }$

$:\implies\: \sf{240= 48x}$

$:\implies\: \sf{x=\dfrac{240}{48} }$

$\sf:\implies\underline{\boxed{\pink{\mathfrak{x = 5}}}}$

Therefore,

Parallel sides of the trapezium,

✮ 5x = 5 × 5 = 25 cm

✮ 3x = 3 × 5 = 15 cm