Why is the `C-O-H` bond angle in alcohols slightly less than the tetrahedral angle whereas the C-O-C bond angle in ether is slightly greater?

The C-O-H bond angle in alcohols is slightly less than the tetrahedral angle whereas the C-O-C bond angle in ether is slightly greater because

The R-O-R bond angle in ether is

In ethers, the C-O-C bond angle is