If the area of the trapezium whose parallel sides are 6 cm and 10 cm is 32 sq. cm, then the distance between the parallel sides is
Aptitude
Area
Difficulty: Easy
Choose an option
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A2 cm
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B4 cm
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C5 cm
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D8 cm
Answer
Correct Answer: 4 cm
Explanation
### Concept & Formula
To find the height when the area and parallel sides are given, rearrange the standard area formula for a trapezium.
$$Area = \frac{1}{2} \times (Sum\ of\ parallel\ sides) \times height$$
$$h = \frac{2 \times Area}{a + b}$$
### Step-by-Step Solution
* **Given:** Area = $32\text{ cm}^2$, side $a = 6\text{ cm}$, side $b = 10\text{ cm}$.
* **Substitute into Formula:**
$32 = \frac{1}{2} \times (6 + 10) \times h$
* **Solve for $h$:**
$32 = \frac{1}{2} \times 16 \times h$
$32 = 8 \times h$
$h = \frac{32}{8} = 4\text{ cm}$.
### Exam Strategy & Shortcut
Find the average of the parallel sides: $(6 + 10) / 2 = 8$. The area is this average multiplied by the height. So, $8 \times h = 32$, which immediately gives $h = 4$.
### Common Pitfall
Adding the parallel sides but forgetting to divide by 2, setting up the equation as $32 = 16 \times h$, which leads to the incorrect answer of 2.
### Final Answer
Therefore, the correct answer is **4 cm**.