A man convicted of raping a vulnerable and frail elderly woman after breaking into her Perth home has been sentenced to more than 17 years in prison.

Mugahed Adam Eldouma, 40, got into the 76-year-old victim's Armadale house in June 2018 through a window and sexually assaulted her before being apprehended and claiming to police that he was the woman's carer.

The case was heard in the District Court of WA. Credit:Emma Young

In the District Court of WA on Thursday, Eldouma was jailed for 17 years and six months for the daytime attack which Judge Bruce Goetze described as "appalling".

"The state of the house probably indicates that she was unable to really look after herself in the home," the judge said.