"steeply angled mansard roofs"

The Château de Dampierre, Dampierre-en-Yvelines, France, garden facade
Creative Commons Attribution Share AlikeThe Château de Dampierre, Dampierre-en-Yvelines, France, garden facade - Credit: Patrick Giraud (aka Calips at fr.wikipedia
The mansard, or French roof, was established in the 17th century by François Mansart, and became very popular during the Second French Empire in the mid-19th century.

Mansards have two slopes to each side, with the lower slope being the steeper.  The steep pitch, coupled with dormer windows, allows the roof to be used for living space.