http://folk.ntnu.no/stoylen/strainrate/mathemathics/ [Broken](adsbygoogle = window.adsbygoogle || []).push({});

This page shows how to find shear strain in three dimensions.

I understand how they found the shear strains as x and y components from dividing the change in length by the original length.

But from the line "From the figure, it is also evident that..." I cannot understand how they combined the strains from the x and y axes to find the functions of tan.

Also, how after I have found the functions of tan, how do I use approximation of small angles to find that the strains actually simply equals the angle itself? I have seen some other websites using sin instead of tan.

Thanks

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# Shear strain

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