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`and`(V = `*`(Pi, `*`(`^`(r, 2), `*`(a))), `and`(`*`(Pi, `*`(`^`(r, 2), `*`(a))) = `*`(`*`(`*`(Pi, `*`(a)), `*`(`^`(a, 2))), `*`(`/`(`+`(`*`(4, `*`(`^`(Pi, 2))))))), `*`(`*`(`*`(Pi, `*`(a)), `*`(`^`(a... 

r = `*`(a, `*`(`/`(`+`(`*`(2, `*`(Pi))))))