If arc gbd is 280 what is the measure of angle 3?

To determine the measure of angle 3, we need more context about the relationship between arc gbd and angle 3. If angle 3 is an inscribed angle that subtends arc gbd, then the measure of angle 3 would be half the measure of arc gbd. Therefore, if arc gbd is 280 degrees, angle 3 would measure 140 degrees.