Answer:
Cinder cones form around a volcanic vent. Lava explodes into the air and cools very quickly forming accumulating a ring of volcanic fragments (like scoria or tuff) around the vent. They are not very tall or strong because there is nothing cementing the fragments together. Their slope never exceeds the angle of repose (approximately 45 degrees). They are not associated with any specific type of lava. Any flavour is possible.