View Compilation Error

0_0_39407813_29749.cpp: In function 'int main()':
0_0_39407813_29749.cpp:42:44: error: 'sqrt' was not declared in this scope
   42 |                                 re[i][j] = sqrt((is[i].x - is[j].x) * (is[i].x - is[j].x) + (is[i].y - is[j].y) * (is[i].y - is[j].y));
      |                                            ^~~~