Is the centre of a circle always equal distance from all points on the circumference? and why

Yes, the center of a circle is always and always equidistant from all the points on circumference because that is because what a circle is called. The distance from the center of the circle to the circumference is called the radius and it is constant for any particular circle.

6 meters

step-by-step explanation:

m∠5 + m∠3 = m∠1   is true.

m∠5 + m∠6 = 180 is true

m∠2 +m∠3 = m∠6   is true

m∠2 +m∠3 +m∠5 = 180   is true