figure: ar-a3-track.png A running track has two straight sides of 90 m each and two semicircular…

Step 1. The outer edge. $2 \times 90 + 2 \times \dfrac{22}{7} \times 35 = 180 + 220 = 400\ \text{m}$.

Step 2. The inner edge. $180 + 2 \times \dfrac{22}{7} \times 28 = 180 + 176 = 356\ \text{m}$.

Step 3. The straight strips. $2 \times 90 \times 7 = 1260\ \text{m}^2$.

Step 4. The ring. $\dfrac{22}{7}\,(35^2 - 28^2) = \dfrac{22}{7} \times 441 = 1386\ \text{m}^2$.

Step 5. The area of the track. $1260 + 1386 = 2646\ \text{m}^2$.