# Discussion on: Solution to Problem 115 Shear Stress

Following is a discussion on the Reviewer item titled: Solution to Problem 115 Shear Stress. Feel free to add your own comments!

### the area?

why is that the area of pi(r)squared all over 4 are not use in this problem?thanks

### Re: the area?

cause, only the out surface of the punch have shear stress. I think so LOL

### Re: the area?

thanks. it make sense..:-)

### How did thry use thr height ,

How did thry use thr height , I mean why pie inti 20 into 25, is it r e rectangle formula

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