suppose AB is thge diameter of a circle

C is any pt on the circumfernce of the circle.
wht is the measure of angle <ACB?

To find the measure of angle <ACB, we need to understand the relationship between the angles in a circle and the concept of intercepted arcs.

In a circle, an angle formed by two radii will always have a measure of 90 degrees (a right angle) since the radii are perpendicular bisectors of the diameter. Therefore, angle <ACB would be a right angle if C was on the diameter AB.

However, since C is a point on the circumference of the circle, the measure of angle <ACB will be different. The measure of the angle will be half the measure of the intercepted arc ACB.

To find the measure of intercepted arc ACB, we need to know the length of the arc or the ratio of the arc to the circumference of the whole circle. Let's assume we have this information.

If we know the length of the arc ACB, we can find the ratio of the arc to the circumference by dividing the length of the arc by the circumference. Let's call this ratio "r".

Once we have the ratio, we can calculate the measure of angle <ACB by multiplying the ratio by 360 degrees (the total measure of all angles in a circle).

So, to summarize, to find the measure of angle <ACB:
1. Find the length of the arc ACB or the ratio of the arc to the circumference.
2. Calculate the ratio "r" by dividing the length of the arc by the circumference.
3. Multiply the ratio "r" by 360 degrees to get the measure of angle <ACB.

Note: If you do not have the length of the arc or the ratio of the arc to the circumference, you will need additional information to find the measure of angle <ACB.