This Zrównoważenie Portfolio icon is made in Material Design style developed by Google. This style is based on extremely simplified shapes, thin two-pixel lines, and is optimized for 24x24 px. Unlike other vector icon packs that have merely hundreds of icons, this icon pack contains 4,300 icons, all in the same style and quality.
It is a pie chart divided into three section. The top left quarter is its own section, then the rest of the chart is divided in half by a diagonal line going from the center of the circle to the bottom right. There is a smaller slice of the chart superimposed over the chart in the upper right.