In old style math, a span of a circle or circle is any of the line fragments from its middle to its edge, and in more current utilization, it is additionally their length.

In math, the circumference is the edge of a circle or oval.

A digression (tangent) to a circle is a straight line which contacts the circle at just one point.

A perpendicular bisector of a line section is a line fragment opposite to and going through the midpoint of (left figure).

Steps for constructions:

1. First draw a line$AB=8cm$using a ruler with correct measurements.

2. At A, draw a circle of radius$3cm$using the compass mark and arc and then draw the circle.

3. At B, draw a circle of radius$3.5cm$again using a compass mark an arc and the draw the circle.

4. Draw a third circle concentric to the smaller circle and radius, at A.

= 3.5 + 3 = 6.5 cm$=3.5+3=6.5cm$

5. Then draw a perpendicular bisector of AB, consider H be the mid-point of AB.

6. Consider ‘H’ as center and AH as radii, draw a fourth circle. Name them G and I where the third and fourth circles intersect each other.

7. Now, join AG and AI to meet the smaller circle at E and C.

8. Then join BG and BI.

9. On BG and BI, draw perpendicular to meet the bigger circle at F and D.

10. Now join EF and CD they will be the tangents and both are of $8cm$.