Answer:
![\text{a) }1,080^(\circ), \\\text{b) }360^(\circ), \\\text{c) }135^(\circ), \\\text{d) }45^(\circ)](https://img.qammunity.org/2022/formulas/mathematics/college/v6y1ffqdky2jgwnzv1hzg1rfd0bc1howpu.png)
Explanation:
a) The sum of the interior angles of a polygon with
sides is equal to
. Since an octagon has 8 sides, substitute in
:
![(6-2)180=\boxed{1,080^(\circ)}](https://img.qammunity.org/2022/formulas/mathematics/college/xkrjot9rf30plj669otl5obxc42cew5yyz.png)
b) The sum of the exterior angles for any polygon is equal to
.
c) By definition, all regular shapes have equal angles and sides. Since we've found the total sum of the interior angles of an octagon in part a, each interior angle of a regular octagon must be
![(1080)/(8)=\boxed{135^(\circ)}](https://img.qammunity.org/2022/formulas/mathematics/college/ilothitdzmckf4wrkxo03epcckjnl2dfce.png)
d) Similar to part c, all regular shapes must have equal angles and sides. From part b, we know the sum of the exterior angles of a octagon is
, thus we have
![(360)/(8)=\boxed{45^(\circ)}](https://img.qammunity.org/2022/formulas/mathematics/college/a2eeq3wp75mvxtmw23gst00nc8dk7l11e3.png)