The breadth

Let the breadth of first rectangle be 2x and length be 3x

In another rectangle, breadth is 1 centimetres less and length is 3 centimetres less than those of the first, this is 3 : 4

⇒

⇒ 4× (2x - 1) = 3 × (3x – 3)

⇒ 8x – 4 = 9x – 9

⇒ -4 + 9 = 9x – 8x

⇒ x = 5

Dimension of first rectangle:

Length = 3× 5 = 15 cm

Breadth = 2 × 5 = 10cm

Dimension of second triangle:

Length = 12 cm

Breadth = 9 cm