Area of triangle by integrals (is this right?)

• silicon_hobo
In summary, the conversation discusses using integrals to find the area of a triangle with vertices (0,5), (-2,-2), and (2,2). There is some confusion about the method, but it is eventually confirmed that the area of the triangle is 10. The conversation also mentions how to mark the thread as solved.
silicon_hobo
[SOLVED] area of triangle by integrals (is this right?)

Homework Statement

Use integrals to find the area of a triangle with vertices (0,5),(-2,-2),(2,2).

The Attempt at a Solution

I think I've got it. I'm just looking for some confirmation of my method before I move on.
Thanks for your time. Cheers.

http://www.mcp-server.com/~lush/shillmud/quest3.jpg

P.S. How do I add a [Solved] to the title?

Last edited:
How are you getting e.g. integral of 5x/2+5 to be 5x^2/4+5x^2/2??

Ooops. Thanks for pointing that out Dick. I found the dx of 5x instead of the dx of 5 which interestingly seems not to have affected my answer. I guess you can see why I'm using the forum. Everything should be in order now. Cheers.

silicon_hobo said:
Ooops. Thanks for pointing that out Dick. I found the dx of 5x instead of the dx of 5 which interestingly seems not to have affected my answer. I guess you can see why I'm using the forum. Everything should be in order now. Cheers.

If you are still getting 20 for the area, I can't agree with that. Double check again.

Okay, I went through again and got A=10. When putting in values for x to solve I sub the rightmost value from the top of integral sign and then subtract from that the same antiderivative with the leftmost x value (top of the integral sign). This is correct? Thanks!

Yes, A=10 works.

Thanks Dick. Heron's method confirms it. Now how do I mark this one [SOLVED] ?

Under Thread Tools, at the top, isn't there a "Mark this thread as solved"?

What is the formula for finding the area of a triangle using integrals?

The formula for finding the area of a triangle using integrals is: A = 1/2 * ∫ f(x) dx, where f(x) is the function representing the side of the triangle.

How do you set up the integral to find the area of a triangle?

To set up the integral to find the area of a triangle, you need to find the function that represents the side of the triangle and then integrate it with respect to the variable that the function is in terms of.

Can you use integrals to find the area of any type of triangle?

Yes, integrals can be used to find the area of any type of triangle, as long as you have a function that represents the side lengths.

Is finding the area of a triangle by integrals more accurate than using the traditional formula A=1/2 * base * height?

Both methods will give you the same result, but using integrals can be more accurate when dealing with irregularly shaped triangles.

Are there any other applications of using integrals to find the area of a triangle?

Yes, integrals can also be used to find the area of other 2D shapes, such as circles, ellipses, and even irregular shapes.

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