Vs reports cmath (19): Error c2061: syntax error: identifier "ACO" error

This is because I used it in the. c file.

# Include <iostream>

Using namespace STD;

In this way, the following is reported during compilation:

The error type is as follows:
1> C: \ Program Files (x86) \ Microsoft Visual Studio 10.0 \ Vc \ include \ cmath (19): Error c2061: syntax error: identifier "ACO"
1> C: \ Program Files (x86) \ Microsoft Visual Studio 10.0 \ Vc \ include \ cmath (19): Error c2059: syntax error: ";"
1> C: \ Program Files (x86) \ Microsoft Visual Studio 10.0 \ Vc \ include \ cmath (19): Error c2061: syntax error: identifier "asinf"
1> C: \ Program Files (x86) \ Microsoft Visual Studio 10.0 \ Vc \ include \ cmath (19): Error c2059: syntax error: ";"
1> C: \ Program Files (x86) \ Microsoft Visual Studio 10.0 \ Vc \ include \ cmath (20): Error c2061: syntax error: identifier "atanf"
1> C: \ Program Files (x86) \ Microsoft Visual Studio 10.0 \ Vc \ include \ cmath (20): Error c2059: syntax error: ";"
1> C: \ Program Files (x86) \ Microsoft Visual Studio 10.0 \ Vc \ include \ cmath (20): Error c2061: syntax error: identifier "atan2f"
1> C: \ Program Files (x86) \ Microsoft Visual Studio 10.0 \ Vc \ include \ cmath (20): Error c2059: syntax error: ";"

Solution:

Change the. c suffix to. cpp.

Vs reports cmath (19): Error c2061: syntax error: identifier "ACO" error