Length = 7u (2r + 15cm)

Breadth = 4u (2r)

7u – 4u = 3u

3u = 15cm

1u = 15cm ÷ 3 = 5cm

Length = 7u = 7 x 5cm = 35cm

Breadth = 4u = 4 x 5cm = 20cm

Radius of quadrant = 20cm ÷ 2 = 10cm

Area of 4 quadrants (1 circle) = 3.14 x 10cm x 10cm = 314cm2

Area of rectangle = 35cm x 20cm = 700cm2

Area of shaded = 700cm2 – 314cm2 = 386cm2

Hope you understand! :))