Calculate Area of Triangle in 3D with Given Vertices | Homework Solution

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To calculate the area of a triangle in 3D with vertices (2,0,0), (0,3,0), and (0,0,6), the initial approach using a determinant is incorrect as it calculates the volume of a parallelepiped instead. The correct formula for the area involves using the base and height, or alternatively, the cross product of two vectors formed by the triangle's edges. A sketch can aid in visualizing the triangle's dimensions. The correct area is determined to be 3√14, highlighting the importance of using the right geometric principles. Understanding the distinction between volume and area is crucial in this context.
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Homework Statement


The vertices of triangle are (2,0,0) ; (0,3,0) ; (0,0,6) . Find the area of triangle.


Homework Equations





The Attempt at a Solution


is it right that i put in determinant like
Area of triangle =
0.5 | 2 0 0 |
| 0 3 0 |
| 0 0 6 |
= 0.5 (2* 3 * 6)
= 18 .

but i think this method is wrong ... the answer of this question is 3 sqrt ( 14) .
 
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In your approach what you are doing is not the area of a triangle.

You are actually finding the volume of a parallelepiped.

The area of the triangle will always be A= \frac{1}{2} *base*heightYou have points so you can find the lengths of the base and height.

A quick sketch may be needed.
 
It's also half the length of the cross product of two difference vectors along the edges of the triangle. You can use a determinant type form to work out the cross product.
 
Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

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