MHB Area of the parallelogram when diagonal vectors are given.

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To find the area of a parallelogram when the diagonals are given, the diagonals can be represented as vectors, specifically $$\alpha = 2i + 6j - k$$ and $$\beta = 6i - 8j + 6k$$. The area can be calculated using the formula $$A = \frac{1}{2} \cdot \| \vec{\alpha} \times \vec{\beta} \|$$. This approach allows for the determination of the area based on the cross product of the diagonal vectors. Understanding the relationship between the diagonals and the sides of the parallelogram is crucial for this calculation. The method effectively provides a means to compute the area without needing the side vectors directly.
Suvadip
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I can find the area of the parallelogram when two adjacent side vectors are given. But how to find the area of the parallelogram when diagonals of the parallelogram are given as

$$\alpha = 2i+6j-k$$ and $$\beta= 6i-8j+6k$$
 
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suvadip said:
I can find the area of the parallelogram when two adjacent side vectors are given. But how to find the area of the parallelogram when diagonals of the parallelogram are given as

$$\alpha = 2i+6j-k$$ and $$\beta= 6i-8j+6k$$
Hint: If the diagonals of a parallelogram are known then you can find the sides. Figure out how.
 
suvadip said:
I can find the area of the parallelogram when two adjacent side vectors are given. But how to find the area of the parallelogram when diagonals of the parallelogram are given as

$$\alpha = 2i+6j-k$$ and $$\beta= 6i-8j+6k$$

Here is a slightly different way to calculate the area of a parallelogram:

According to your question $$\alpha$$ and $$\beta$$ denote the diagonals of a parallelogram. Then the area is

$$A = \frac12 \cdot \| \vec {\alpha} \times \vec {\beta} \|$$
 
Here is a little puzzle from the book 100 Geometric Games by Pierre Berloquin. The side of a small square is one meter long and the side of a larger square one and a half meters long. One vertex of the large square is at the center of the small square. The side of the large square cuts two sides of the small square into one- third parts and two-thirds parts. What is the area where the squares overlap?

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