What is the formula for interior angle sum

Step-by-step explanation:

The sum of an interior angle of a regular polygon varies and it is given by the formula

θ=(n-2)×180°

Where,

θ is the sum of angle in the polygon

n is the total sides of the polygon.

Let analyze some shapes

1. Triangle

A triangle has 3 sides and 3 angles

Then, n=3

So, θ=(n-2)×180°

θ=(3-2)×180°

θ=1×180°

θ=180°

So, that is why the sum of angle in a triangle is 180°

2. Decagon,

Decagon has 10 sides

n=10

θ=(10-2)×180°

θ= 8×180°

θ=1440°

Sum of angle in a decagon is 1440°

You can try all this

n=4. quadrilateral

n=5. Pentagon

n=6. Hexagon

n=7. Heptagon

n=8. Octagon

n=9 Nonagon

i think is 3 and 6. this took me 10 min to think.hope to and hope that my answer is brainliest.(follow me )

step-by-step explanation: