25[ 17√7/32+arccos( 1/8)-3 arcsin(9/ 16)]

Need to use the definite integral of advanced mathematics,

Those who think that elementary school knowledge can solve it,

Please don't comment,

Don't insult the wisdom of netizens with your IQ.

If you're sure you can understand my answer,

It uses inverse trigonometric function and root sign,

It can't be a primary school problem.

You can ask me my process!

Look at this question. Yes,

Actually, I don't think it's necessary to solve the problem.