Q: Why is Pages running so slow in Yosemite?

Hey darylgt,

That is not a good time especially if you are trying to get some work done. If at any time you are having slowness or the fans running loud, take a look at the article below and look at Activity Monitor to see if there is a high CPU performance or apps using a lot of memory that would affect your performance. Let me know if that helps or need further assistance. 

Apps can affect Mac performance, battery runtime, temperature, and fan activity

https://support.apple.com/en-us/HT203184

Take care,

-Norm G.