Define natural hazard?
A natural hazard is a natural phenomenon that might have a negative effect on humans and other animals, or the environment. Natural hazard events can be classified into two broad categories: geophysical and biological.
What is the difference between tectonic hazards and weather hazards ?
Tectonic hazards occur when the Earth's crust moves. For example, when the plates move, friction can cause them to become stuck. Tension builds until the plates release, which leads to an earthquake. Climatic hazards occur when a region has certain weather conditions, for example heavy rainfall can lead to flooding.
why do convection currents in the mantle occur?
Heat rising and falling inside the mantle creates convection currents generated by radioactive decay in the core. The convection currents move the plates. Where convection currents diverge near the Earth's crust, plates move apart
If AC must be parallel with BD and m∠6 is doubled, m∠3 must be doubled too.
This is because of the following rule:
When two lines are parallel, which is the occasion with AB and CD, then the corners in which the intecepting parallel lines (AC and BD) stand must be the same. So corner 6 is equivalent to corner 3, corner 1 and corner 5. Corner 2 and corner 4 are equivalent too.
