Given,
Length of the courtyard = 45 m
Breadth of the courtyard = 35 m
Courtyard is in the shape of a rectangle.
We know that perimeter of a rectangle = 2 x (length + breadth)
Perimeter of the courtyard
= 2 (45 + 35) m
= 2 × 80 m
= 160 m
Distance covered by the boy in taking 5 rounds of the courtyard
= 5 × perimeter of the courtyard
= 5 × 160
= 800 m