Question

the area for trapezium is 405 centimetres square and the ratio of parallel sides is 4:5 and height is 18 centimetres find the actual length of the parallel sides.​

No spam✔

Answer 1

Given:

Area of the trapezium = 405cm²

ratio of parallel sides = 4:5

height of the trapezium = 18cm

To Find:

Actual length of the parallel sides

Solution:

Let the parallel side be 4x and 5x respectively

height = 18cm

the area of trapezium = 405cm²

⠀⠀⟹$\frac{1}{2} h(a + b) = 405$

⠀⠀⟹$\frac{1}{2} \times 18 \times (4x + 5x) = 405$

⠀⠀⟹ $9 \times 9x = 405⟹9×9x=405$

⠀⠀⟹ $81x = 405⟹81x=405$

$\: x = \frac{405}{81} = 5$

➞actual Length of parallel side 1 = 4 × 5

${\boxed{\sf{\red{=\:20\:cm}}}}$

➞actual Length of parallel side 2 = 5 × 5

${\boxed{\sf{\red{=\:25\:cm}}}}$

Answer 2

Answer:

Given:

Area of the trapezium = 405cm²

ratio of parallel sides = 4:5

height of the trapezium = 18cm

To Find:

Actual length of the parallel sides

Solution:

Let the parallel side be 4x and 5x respectively

height = 18cm

the area of trapezium = 405cm²

⠀⠀⟹

$\frac{1}{2}$

h(a + b) = 405

h(a+b)=405

⠀⠀⟹

$\frac{1}{2} \times 18 \times$

(4x + 5x) = 405

×18×(4x+5x)=405

⠀⠀⟹ 9 \times 9x = 405⟹9×9x=4059×9x=405⟹9×9x=405

⠀⠀⟹ 81x = 405⟹81x=40581x=405⟹81x=405

x=

$\frac{405}{81}$

=5

➞actual Length of parallel side 1 = 4 × 5

=20cm

➞actual Length of parallel side 2 = 5 × 5

= 25

Step-by-step explanation:

5 is your answer