Hello,
First thing to do, assuming this is a new install, is to
check to see if all the dependancies for apache and php have been met for it to work. Best way to check is to look at installed packages and verify them.
If it looks like apache and php are installed correctly to run with each other, run phpinfo().
You may or may not see this: --with-apache=../apache_1.3.12
or there is some other one --with-apx......
I have been through more rh installs than I care to remember, and I have not had any issues like this one.
You may want to check the apache error logs to see if thier are any warnings or errors about php.
Good Luck...