B shadows
The position of the sun in the sky casts a shadow on a properly placed sundial. This will give you time of day depending where the shadow falls.
Angola's borders are fairly straight compared to borders of any other country. The coastline and the southern lines are straight while the eastern and northern borders have stair-like shape but are fairly straight too. The country looks like a gun in some way too!
This is known as the visible spectrum of electromagnetic radiation, or visible light. This is the frequency of light that we see, and which illuminates our world as it reflects off of objects. Compared to the full spectrum of electromagnetic radiation, the visible light portion is actually quite small.
Answer:
Photograph: bird's eye view of a site; interview: personal analysis and biased; tax records: limited accessibility; biography: unreliability of human memory.
Explanation:
There are generally always some drawbacks when considering different sources of historical information and a good researcher has to take these factors into account. Photographs are limited because they give you very little context. Interviews can be limiting because you get a personal view from just one individual. Tax records are likely protected due to privacy concerns and statutes. Biography can have drawbacks as well because the person may embellish past events or overemphasize the significance or attribute meaning in ways that are not entirely truthful or objective.
