When you have 3 separate circles and the radius of each of those circles is 10 do i calculate like this? 2(10)+2(10)+2(10)=60 cm for my diameter

I'm not sure if there is a given figure for this problem, but if the three separate circles are tangent with the other with their centers aligned (or can be connected by a straight line), then yes, you get 60 cm for the diameter of the new, bigger circle which circumscribes on the three smaller circles.

There are 3 separate circles, there is a chord drawn through the center of each circle, the point of tangency is on the third circle. So i drew a line perpendicular from the radius of 10 in the third circle to the point of tangency.

This is the entire question(Each of the three circles in the figure has a radius of 10. The line OA contains the centers of the three circles, and the line OB is tangent to the right-hand circle. Find the length of segment CD.

Is there a way to submit my picture?

I solved it. the length of segment CD with by 20 cm. Thank you

No, you do not calculate the diameter by adding the perimeter of the circles. The perimeter (circumference) of a circle is calculated using the formula: circumference = 2πr, where π is a constant (approximately 3.14159) and r is the radius of the circle.

In this case, the radius of each circle is 10 cm. Therefore, the circumference of each circle is 2π(10) = 20π cm.

If you want to calculate the total diameter when you have three separate circles with a radius of 10 cm each, you need to double the radius. The diameter is equal to two times the radius, so in this case, the diameter of each circle is 2(10) = 20 cm.

However, if you want to find the total length of the three circumferences, you would add them together. In that case, it would be 3(20π) = 60π cm (or approximately 188.5 cm).