Q2 of 59 Page 203

Let's write by calculation the sum of measurement of eight interior angles of an octagon.

We know that, if a polygon has ‘n’ sides, then it divides in (n – 2) triangles.

We also know that, by angle sum property that


Sum of the angles of a triangle = 180°


∴ the sum of angles of (n – 2) triangle = (n – 2) × 180°


Now, we have to find the sum of eight interior angles of octagon.



So, the number of sides in OCTAGON = 8


Sum of 8 interior angles of octagon = (n – 2) × 180°


= (8 – 2) × 180°


= 6 × 180°


= 1080°


Hence, the sum of measurement of eight interior angles of an octagon is 1080°


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8

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