A regular polygon has n sides - OCR - GCSE Maths - Question 11 - 2018 - Paper 6
Question 11
A regular polygon has n sides.
The polygon's interior angle is 5 times the size of its exterior angle.
Find n.
Worked Solution & Example Answer:A regular polygon has n sides - OCR - GCSE Maths - Question 11 - 2018 - Paper 6
Step 1
Find the relationship between the interior and exterior angles
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Answer
Let the exterior angle be denoted as x. Therefore, the interior angle can be expressed as 5x.
We know that the sum of the interior and exterior angle is:
extInteriorAngle+extExteriorAngle=180
This gives us:
5x+x=180
Step 2
Solve for x
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Answer
Combining the terms gives:
6x=180
Dividing both sides by 6 results in:
x=30
Thus, the exterior angle is 30 degrees.
Step 3
Calculate the number of sides n
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Answer
The formula to find the number of sides n of a regular polygon is given by:
n=Exterior Angle360
Substituting the value of the exterior angle, we have:
n=30360=12