I'm looking for a way to speed up my work in blender, i have a mesh, decagon polygon. I want to select all the vertex similar like in the picture below. Is there a quick way to do this ? without doing everytime with mouse. I found the SHIFT+G option but it didn't resolve my problem. Thank you
The simplest way to select everything in that loop but vertices in the middle is to use Shift+G > By Length in Edge selection mode. Select one long edge from the loop and run Select Similar command.
Then convert that selection to the pattern shown on your screenshot by changing Selection mode to Vertex.
However this way may not be the best since it will select all the edges falling under the specified length threshold (length of the active edge).
Another way is to use Checker Deselect to deselect vertices you don't need to be selected according to certain pattern.
First select the edge loop with Alt+RMB on it. Then deselect and select again vertex in between long edges to make it active. Run Checker Deselect from Select menu in the viewport footer or from the Spacebar menu. Change its settings to Nth Selection - 2 (to deselect every 2nd element), Skip - 2 (to skip every 2 steps of selection) and Offset - to 2 (to offset the start of selection).