regular polygon angle measures
octagon
sum of interior angles: 1080° each interior angle: 135° sum of exterior angles: 360° each exterior angle: 45°
nonagon
sum of interior angles: 1260° each interior angle: 140° sum of exterior angles: 360° each exterior angle: 40
decagon
sum of interior angles: 1440° each interior angle: 144° sum of exterior angles: 360° each exterior angle: 36°
triangle
sum of interior angles: 180° each interior angle: 60° sum of exterior angles: 360° each exterior angle: 120°
quadrilateral
sum of interior angles: 360° each exterior angle: 90° sum of exterior angles: 360° each exterior angle: 90°
Pentagon
sum of interior angles: 540° each interior angle: 180° sum of exterior angles: 360° each exterior angle: 72°
Hexagon
sum of interior angles: 720° each interior angle: 120° sum of exterior angles: 360° each exterior angle: 60°
heptagon
sum of interior angles: 900° each interior angle: 128 and 4/7° sum of exterior angle: 360° each exterior angle: 51 and 3/7°
polygon with 'n' sides
sums of interior angles: n-2(180) each interior angle: (n-2(180)) divided by n sum of exterior angles: 360° each exterior angle: 360/n