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

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SUMMARY

The area of a triangle in 3D space with vertices at (2,0,0), (0,3,0), and (0,0,6) is calculated using the cross product of two vectors formed by the vertices. The correct formula for the area is A = 0.5 * |AB x AC|, where AB and AC are vectors along the triangle's edges. The area is determined to be 3√14, contrasting with the incorrect method that calculated the volume of a parallelepiped using a determinant. This highlights the importance of using the appropriate geometric principles for area calculation in three-dimensional geometry.

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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.


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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.
 

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