Pie Graph.
a "circle graph" is also a polar graph, it's used to graph polar coordinates.
the firt and second graph should be circled 2. the bar graph 3. the line graph
The mathematical technique used to calculate the area under a graph is integral calculus. This is a complex subject which I am not going to attempt to explain in detail- it normally takes years of study.
Line Graph, and I know that these are Study Island questions.
One graph used to relate stars' absolute magnitudes and their spectral types is the Hertzsprung-Russell diagram, better (and more simply) known as the H-R diagram.
Pie Graph.
HR Graph of Star Sizes
telescopes
telescopesA telescope,books to study and find out what types of stars/constellations there are and maybe a astrolabe?
Telescopes.
Telescopes
The study of the stars is astronomy.
Spectroscope
Why did Asians study stars
Astronomy is the study of space and stars are in space, so astronomy deals with the study of stars.
Arecibo