1, the calculation of bend length, the sum of the lengths of two bends in a semi-circular track and field is exactly equal to the circumference of a circle. According to the circumferential formula C=2πr, the length of the two bends in the first lane (calculated line length) is:

2× 3.1416× (36+0.30) m = 228.08m The length of a bend is 228.08 ÷ 2 =114.04m.

2. Calculation of straight line segment

Length of two straight lines = total length of runway-length of two curves.

= 400m–228.08m =171.92m.

The straight line segment is171.92m÷ 2 = 85.96m.

3. Runway length calculation Runway length = two bends+two straight lines.

=228.08m+ 17 1.92m

= 400 meters

(2) Calculation of bend length of each branch (taking lane width1.22m as an example)

According to the circumferential formula C=2πr

Cn=2π[r+(n- 1)d+0.20]

(c stands for the circumference of the bend, n stands for the number of passes, r stands for the radius of the site, and d stands for the width of the lane)

(3) Calculation before the starting line extends forward

If two athletes with lane separation run 1 week according to their own lane separation, the athlete with lane separation 2 will run 7.04m more than the athlete with lane separation 1. In order to make the distance of the second lane equal to the distance of the runner running 1 lane, the starting point must extend forward for a certain distance. The distance that should be extended forward is called the number of times to extend from the starting line. The method of calculating the start line extension is to subtract the curve length of 1 lane from the curve length of a lane, which is the start line extension number of the lane. The formula is as follows:

wn = 2π[r+(n- 1)+0.20]-2π(r+0.30)