Geography 2005 Jamb Examination

The principle of similar triangles is applied in chain surveying mainly when an obstacle such as a river or structure prevents direct measurement along the survey line.
By forming similar triangles, the surveyor can indirectly obtain the required length without crossing the obstacle.
This allows accurate determination of distances even when the line is blocked, making it an essential method for overcoming obstacles.

A linear scale shows the relationship between distances on the map and corresponding distances on the ground. It is primarily used to measure ground distances accurately.
Since distances measured can subsequently be used to determine areas, linear scales help in calculating both distances and areas on maps, but they do not deal with volumes or directions.
Thus only distances and areas are directly measurable using the linear scale.

The Atlas Mountains stretch across the north-western part of Africa. They extend through Morocco, Algeria and Tunisia, but the largest and most prominent portions are located in Morocco.
The High Atlas, Middle Atlas and Anti-Atlas ranges are predominantly Moroccan, making Morocco the principal location of the Atlas mountain system.

Coal was first discovered in commercial quantities at Udi Hills in the early 20th century. This subsequently led to the establishment of the coal-mining settlement at Enugu, which later grew into a major urban centre.
Enugu became known as the "Coal City" due to its origins linked directly to coal exploration and mining activities.

Cities with populations exceeding one million are classified as megacities or major metropolitan areas. Cairo, Lagos, Kinshasa and Johannesburg are all well-established megacities in Africa, each exceeding the one-million threshold by a wide margin.
The other options include cities that do not all meet or exceed this population size, making only the last group consistently within the one-million-plus category.

Inselbergs are isolated hills or rock outcrops that rise abruptly from surrounding plains. They are typically formed from very old, highly resistant crystalline rocks.
In Nigeria, such formations originate mainly from the Precambrian Basement Complex, which contains hard rocks such as granites and gneisses that resist weathering.
The long-term differential weathering of these rocks produces the characteristic steep-sided inselbergs found across areas such as the Yoruba and Hausa lands.

Desertification in Nigeria is most severe in the northern states, where rapid population growth places intense pressure on available land resources.
Activities such as overgrazing, deforestation for fuelwood and unsustainable farming practices degrade vegetation cover.
This human-induced pressure leads to soil exposure, increased erosion and the progressive expansion of desert-like conditions, making excessive pressure on land the major driver.

Senegal’s economy has historically relied heavily on agriculture, particularly the cultivation and export of groundnuts. Groundnut production has long been the country’s principal cash crop.
The crop supports both domestic livelihoods and export earnings, forming the backbone of the agro-industrial sector.
While tourism and fishing are significant, they do not surpass groundnut as Senegal’s traditional and dominant foreign exchange earner.

Nigeria’s modern manufacturing expansion has been strongly linked to developments in the petroleum sector.
The growth of the petroleum industry created improved access to energy, an influx of capital and the establishment of petrochemical-based industries, all of which provided essential raw materials for manufacturing.
This linkage ensures that many manufacturing activities expand as the petroleum sector grows.

The Jos Plateau is a major watershed in central Nigeria, providing headwaters for several rivers that drain into surrounding lowlands.
The Gongola River rises in the eastern highlands of the Plateau, the Jama’are River originates from its northern slopes, and the Kaduna River also has its source on the Plateau before flowing south-westward.
This combination makes Jama’are, Gongola and Kaduna the rivers correctly associated with the Plateau.