Find The Area Of A Shape In Form Of A Star

AI Thread Summary
Finding the area of a star-shaped figure is feasible by breaking it down into triangles. The suggested method involves selecting a central point and forming triangles with this point as a vertex, ensuring the star is star-convex. Each triangle shares an arm with the center, allowing for the calculation of the total area by summing the areas of these triangles. Providing specific coordinates for the star's outer and inner points can simplify the area calculation process. Visual aids, such as drawings, can enhance understanding and facilitate the computation.
mathelord
Is It Possible For One To Find The Area Of A Shape In Form Of A Star,i Am Noi Good At Latex Else I Would Have Drawn It,shapes Like The Star,with More Than 5 Pointings
 
Physics news on Phys.org
Well why would it be impossible? The approach I would try would be to break an n-pointed star into 2n triangles. Choose some point and call it the center (the choice should ensure that your figure is star convex about the point). Each of your triangles should have this center as a vertex. Every point should be a vertex of two different triangles, so every line segement which joins a point to the center is an arm shared by two triangles. The sum of the areas of the triangles is the area of the star.

EDIT: Rather than using \LaTeX, you could (and this would work better anyways, I think) draw a picture in Paint and upload it as a .jpg file.
 
akg please give it a try and let me know,what will the base of the triangle be,because you can't form a value for it.
 
I can form a value for it given certain information, but you haven't given me any information. Give me an example of a star and I'll show you how to compute it's area using the technique above. There may be some ways of the defining the star such that the given information makes it difficult to use the technique above, but if, for example, you define the star for me by giving me the co-ordinates of all the "outer" points and all the "inner" points, it will be very easy.
 
Are you referring to area in a general form, i.e. equation or just one particular instance? If just one instance, you'll have 5 triangles and a pentagon. Sum all of the individual areas. A picture would be nice just to make sure though.
 
Thread 'Variable mass system : water sprayed into a moving container'
Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Back
Top