Although Brazil has extensive rivers (e.g., the Amazon and its tributaries), the country lacks a coherent, continuous national waterway network. Navigable reaches exist, but large-scale integration is limited.
Many rivers traverse dense rainforest. Thick riparian vegetation, difficult access, and a lack of robust port infrastructure reduce navigability. Soft banks and seasonal erosion complicate durable port/terminal construction.
Marked seasonal fluctuations in discharge, plus rapids and waterfalls, disrupt continuous navigation. Overcoming these barriers (locks, dredging, channel training) demands heavy capital expenditure that can be hard to justify when traffic demand is sparse or dispersed.
As a result, despite the vast river system, waterways are underutilized relative to roads and rail. Localized corridors function, but they don’t amount to a nationwide, high-capacity inland water transport grid.
\[ \textbf{Brazil’s waterways are underdeveloped due to rainforest access limits, seasonal flows, rapids/waterfalls, and high infrastructure costs.} \]

In the following figure \(\triangle\) ABC, B-D-C and BD = 7, BC = 20, then find \(\frac{A(\triangle ABD)}{A(\triangle ABC)}\). 
The radius of a circle with centre 'P' is 10 cm. If chord AB of the circle subtends a right angle at P, find area of minor sector by using the following activity. (\(\pi = 3.14\)) 
Activity :
r = 10 cm, \(\theta\) = 90\(^\circ\), \(\pi\) = 3.14.
A(P-AXB) = \(\frac{\theta}{360} \times \boxed{\phantom{\pi r^2}}\) = \(\frac{\boxed{\phantom{90}}}{360} \times 3.14 \times 10^2\) = \(\frac{1}{4} \times \boxed{\phantom{314}}\) <br>
A(P-AXB) = \(\boxed{\phantom{78.5}}\) sq. cm.