For Sec 1 Maths students to try
Question
A polygon has an interior angle of 200 degrees. What is the corresponding exterior angle ?
Triangle interior angle 180. Square interior angle = 2xtriangle interior angle.... Pentagon interior angle = 3xtriangle interior angle.... Interior angle of a polygon = (number of sides-2)x180... I dunno of any polygon with interior angle 200....
Begging the question fallacy spotted. Unless its questioning regular polygon and each interior angle is 200...
Edit: Resolved. I was ignorant of concave polygon calculations. I repent. :-)
Agreed; the question is poorly-written.
One interior angle for a regular polygon cannot be 200 degrees, since the sum of one interior angle and its exterior angle is only 180 degrees.
And as aneslayer has pointed out, no regular polygon has a total interior angle of 200 degrees..... it's always in factors of 180 degrees (180, 360, 540, etc.....).
And if it's an irregular polygon, there is insufficient information to proceed. Okay, maybe you can imagine an irregular polygon with one of its internal angles being 200 degrees.... making its exterior angle 160 degrees. But then I would fault the question setter for being so incredibly vague.
The polygon is irregular for this question and the answer for the corresponding exterior angle is NOT 160 degrees.
Okay, then there is insufficient information to proceed.
For a polygon, an internal angle is created at the terminus of two sides. If one angle is a reflex angle of 200 degrees, then the other should be 360 - 200 = 160 degrees (you know, angles at a point).
If it isn't 160 degrees, then there is some other missing piece of information without which this question cannot be solved.
Originally posted by fudgester:Okay, then there is insufficient information to proceed.
For a polygon, an internal angle is created at the terminus of two sides. If one angle is a reflex angle of 200 degrees, then the other should be 360 - 200 = 160 degrees (you know, angles at a point).
If it isn't 160 degrees, then there is some other missing piece of information without which this question cannot be solved.
No other information is needed for this question. This is a simple question that will test the Sec 1 Maths student's understanding of an exterior angle in the not usual way.
This question does not need a lot of calculation.
An exterior angle of a polygon is formed by extending one side of the polygon. For concave polygon, flip out to calculate.
Int angle of fliped out polygon 160. Ext angle = 20.
Originally posted by Aneslayer:An exterior angle of a polygon is formed by extending one side of the polygon. For concave polygon, flip out to calculate.
Int angle of fliped out polygon 160. Ext angle = 20.
For the proper understanding of the definition of an exterior angle, please kindly refer to the url link http://en.wikipedia.org/wiki/Polygon
This question tests the Sec1 Maths student's understanding of an exterior angle in the NOT usual way.
Can I have a cookie?
This thread gives me an idea... I should start a fallacy awareness thread...