746 views
5 votes
The sum of the measures of seven angles of an octagon is 1000 degrees fine the measure of the eighth angle

2 Answers

7 votes
now, we're assuming this is for interior angles.

the sum of all the interior angles in a polygon is

180(n - 2) n = number of sides in a polygon.

now, this is an OCTAgon, it has OCTA=8 sides, so it has a sum of its interior angles at 180( 8 - 2) --> 180(6) ---> 1080°.

now, we already know seven of those eight angles add up to 1000, so... surely you'd know what the last one is.
User Mikael Jansson
by
8.3k points
5 votes

Answer: 80°

Explanation:

We know that the sum of all angles in a polygon having n sides is given by :


(n-2)* 180^(\circ)

For octagon , n= 8

Then, the sum of all angle sin octagon =
(8-2)* 180^(\circ)


=6* 180^(\circ)


=1080^(\circ)

It is given that , The sum of the measures of seven angles of an octagon is 1000 degrees.

Then, the measure of the eighth angle = Sum of all angles - 1000°

= 1080° - 1000° =80°

Hence, the measure of the eighth angle is 80° .

User Gilda
by
8.5k points