Explicit evaluations of the symmetric Euler integral   $\int _{0}^{1}\,{{u}^{\alpha }}{{(1-u)}^{\alpha }}f(u)\,du$  are obtained for some particular functions
 $\int _{0}^{1}\,{{u}^{\alpha }}{{(1-u)}^{\alpha }}f(u)\,du$  are obtained for some particular functions   $f$ . These evaluations are related to duplication formulae for Appell’s hypergeometric function
 $f$ . These evaluations are related to duplication formulae for Appell’s hypergeometric function   ${{F}_{1}}$  which give reductions of
 ${{F}_{1}}$  which give reductions of   ${{F}_{1}}(\alpha ,\beta ,\beta ,2\alpha ,y,z)$  in terms of more elementary functions for arbitrary
 ${{F}_{1}}(\alpha ,\beta ,\beta ,2\alpha ,y,z)$  in terms of more elementary functions for arbitrary   $\beta $  with
 $\beta $  with   $z=y/(y-1)$  and for
 $z=y/(y-1)$  and for   $\beta =\alpha +\frac{1}{2}$  with arbitrary
 $\beta =\alpha +\frac{1}{2}$  with arbitrary   $y,z$ . These duplication formulae generalize the evaluations of some symmetric Euler integrals implied by the following result: if a standard Brownian bridge is sampled at time 0, time 1, and at
 $y,z$ . These duplication formulae generalize the evaluations of some symmetric Euler integrals implied by the following result: if a standard Brownian bridge is sampled at time 0, time 1, and at   $n$  independent randomtimes with uniformdistribution on
 $n$  independent randomtimes with uniformdistribution on   $[0,1]$ , then the broken line approximation to the bridge obtained from these
 $[0,1]$ , then the broken line approximation to the bridge obtained from these   $n+2$  values has a total variation whose mean square is
 $n+2$  values has a total variation whose mean square is   $n(n+1)/(2n+1)$ .
 $n(n+1)/(2n+1)$ .