View Compilation Error

0_0_18786055_9691.cpp: In function 'int main()':
0_0_18786055_9691.cpp:26:3: error: 'else' without a previous 'if'
   else{printf("%.5f\n",pi*sqrt(d*(d-4)+5));}
   ^
0_0_18786055_9691.cpp: At global scope:
0_0_18786055_9691.cpp:28:2: error: expected unqualified-id before 'return'
  return 0;
  ^
0_0_18786055_9691.cpp:29:1: error: expected declaration before '}' token
 }
 ^