What type of volcano typically has broad, gentle slopes and is built by the flow of low-viscosity lava?

The type of volcano characterized by broad, gentle slopes formed by the flow of low-viscosity lava is indeed the shield volcano. Shield volcanoes are named for their resemblance to a warrior's shield lying on the ground, with their broad and shallow profile. This shape is primarily due to the fluid nature of the lava that erupts from them, which allows the lava to travel over great distances before solidifying. The low viscosity of the lava enables it to flow easily and creates the expansive, gentle slopes typical of shield volcanoes.

In contrast, cinder cone volcanoes are steep and built from the accumulation of volcanic debris such as ash and small lava fragments ejected during explosive eruptions. Composite volcanoes feature steep slopes as well, but they are formed through alternating layers of lava flows and explosive eruptions, leading to a more complex structure. Lava domes are formed from the slow extrusion of highly viscous lava, resulting in steep sides and a more dome-like shape. Thus, shield volcanoes are distinct in their formation and structure due to the characteristics of the lava that constructs them.