Can anyone tell me correctly​

1) A figure formed by line segments only is called a polygon .

2) Perimeter of a regular polygon is Number of sides × Measure of each side .

3) Perimeter of a irregular polygon is sum of all sides .

4) Two circles with same centre but different radii is called Concentric circles.

5) Ratio of circumference of circle to its diameter is pie and is named by Greek letter π .

6) Distance around the circle is called circumference.

7) A chord of the circle contains exactly two points on a circle.

8) 1 hectare = 10,000 m²

entering that problem on the tube might get you an answer