SOLUTION: Two of three consecutive sides of regular nonagon(nine sided) are produced to meet at point T. Calculate the size of the angle formed at T.

Algebra.Com
Question 1201837: Two of three consecutive sides of regular nonagon(nine sided) are produced to meet at point T. Calculate the size of the angle formed at T.
Found 2 solutions by math_tutor2020, greenestamps:
Answer by math_tutor2020(3817)   (Show Source): You can put this solution on YOUR website!

Answer: 100 degrees

Explanation:

A regular polygon has equal angles and equal sides.

Let's draw out a regular nonagon with 9 sides.


Highlight 3 consecutive sides.

These are adjacent neighboring sides.
I picked the 3 sides at the bottom marked in red.

Pick two sides, of those 3, that aren't neighbors. Extend them until they meet at point T.


We'll need to know the measure of each interior angle for a regular nonagon.
S = sum of interior angles of a polygon of n sides
S = 180(n-2)
S = 180(9-2)
S = 180*(9-2)
S = 1260
Then we divide that into nine equal pieces
1260/9 = 140
The measure of each interior angle of a regular nonagon is 140 degrees.


Each adjacent pair of angles marked 140 and x are supplementary.
They add to 180 degrees to form a straight line.
x+140 = 180
x = 180-140
x = 40




Focus on the triangle at the very bottom. The three interior angles add to 180.
x+x+T = 180
40+40+T = 180
80+T = 180
T = 180-80
T = 100 is the final answer.

Answer by greenestamps(13200)   (Show Source): You can put this solution on YOUR website!


Extending the two sides to meet at T forms a triangle with the third side of the nonagon in which two of the angles are exterior angles of the regular nonagon.

The measure of each exterior angle of a regular nonagon is 360/9 = 40 degrees.

The sum of the angles of the triangle is 180 degrees, so the measure of angle T is 180-2(40) = 100 degrees.

ANSWER: 100 degrees


RELATED QUESTIONS

Two alternate sides of a regular polygon,when produced,meet at the right angle. calculate (answered by Edwin McCravy)
what it's the nine angles of a nonagon if the other sides are 124... (answered by Alan3354)
AB, BC and CD are three sides of a regular polygon , angle ABC= 144°, AB and CD are... (answered by ikleyn)
A regular nonagon has an area of 121m^2. A similar nonagon has an area of 64m^2. What is... (answered by richard1234)
what is the measure of a nine sided regular... (answered by fractalier)
(GEOMETRY) CONSIDER A REGULAR NONAGON.... 3) Calculate the measure of... (answered by jim_thompson5910)
Find the area of a regular nonagon of side 6cm (answered by josgarithmetic,ikleyn,MathTherapy,Alan3354)
suppose the measures of the interior angles of convex nonagon are nine consecutive whole... (answered by Alan3354)
The nine-pointed star shown here has a regular nonagon at its center. What is the measure (answered by ikleyn)