TO FIND THESE MISSING ANGLES WE USE THE 2n-5(90) formula. n represents the amount of the sides.
Then we add the given angles and subtract it from the value of the shape.
3. The missing angle is 159°
2n-5(90)
2(5)-5(90)
10-5*90=450°
119+89+83=291°
450°-291°=159.
4. The missing angle is 69°
2n-5(90)
2(4)-5(90)
8-5*90=270°
122°+79°=201°
270°-201°=69°
HOPE THIS HELPS!
HAVE A GR8 DAY! ;-)