Q1 E of 59 Page 195

Let’s write the sum of the measurement of the interior angles of the following polygons:

Decagon


For a decagon we know that it has ten sides.

So let us substitute n = 10 in the above formula.


Sum of interior angles is given as = (2 × 10 – 4) × 90


= (20 – 4) × 90


= 16 × 90


= 1440°


More from this chapter

All 59 →
1 C

Let’s write the sum of the measurement of the interior angles of the following polygons:

heptagon


 1 D

Let’s write the sum of the measurement of the interior angles of the following polygons:

octagon


 1 F

Let’s write the sum of the measurement of the interior angles of the following polygons:

a polygon with 12 sides.


 2

The measurement of three angles of a quadrilateral are 104.5°, 65°, 72.5° respectively. Let’s write the measurement of the fourth angle.