Why when i enter A, and the second scanf founction is not work, there are no value for cis.

int main() char in, Cls; int r-0; printf("A: Circle nB: Square C: Triangle "); printf("Enter Which Shape to use: "); scanf("%c", &in); switch(in) [ case A' printf("Enter P for solve for perimeter and A for solve for Area "); printf("Choice: "); scanf(%c", &cis); / /cis is choice printf("Enter circle radius: "); scanf("%lf", &r); printf("Circle perimeterr is:", perimeter('A', 2, 0, e)); return 0