Idea of Topic Icon
A speech bubble is shaped like a circle, with a small portion (about 1/10) open on the bottom left. Two lines are drawn off of this, that extend a short ways before meeting, to close the bubble. It looks like a circle with a small triangle hanging from it.
This is the Topic icon for Windows 10
. Here we go. Optimized for 32x32 px, these are the simplest icons in the line style. Downloadable formats are PNG and SVG, among others. Icons8 icon pack is unique in providing a huge number of icons designed by the same team of four designers who create the new icons every working day in the same style and with the same quality. Same cool as the Bat Face, huh.