Answer:
The shield volcano type es very broad and large in diameter, with gently sloping sides. It must have formed from low viscosity lava (which is also low in silica)
Explanation:
The viscosity of lava depends on different factors, like water, mineral crystals, bubbles and silica content. The silica content is one of the most important factors, because it has a characteristic chemical link between Si and O that can make a flow behave like something between liquid and solid, being more viscous when there is a high amount of silica.
Low vicosity lava flows very easily, almost like water, and for that reason, when a volcano send down this kind of lava, it flows around, reaching larges distances before cooling down and forming a rock, thereby, the structure of the volcano is longer than high and with very gently sloping sides.
