Except that it's all propaganda and lies. Other than that it's "real history."
The "Islamic world" and pre-Islamic Arab world was the middle ground between the much more advanced Hindu Kush and the civilization that grew around the Med and we now call "the West." Virtually all of the things Europe "learned" from Arabs (zero, algebra, chess are the cliche examples) were things they had picked up from the much older and sophisticated Hindu culture in trade with them.
The only thing that Arab/Islamic culture can be credited with is acting as a storehouse and library for the works of their betters in both the east and west that would otherwise have been lost. That is no small achievement, but they cannot claim original invention as this article claims.
Oh, and for a long time scholars like those relied on for this article were trying to sell the notion that the Egyptians who built the pyramids knew about Pi because there was a mathematical relationship between the base of the sides of the Pyramids and the height that involved Pi. That is until they discovered that the builders used a wheel that was on length across (a cubit?) to measure the base by so many turns and then calculated the height based on that same diameter. By definition that involves Pi, but the builders didn't have any way to calculate it. As in this case they confuse result with original knowledge.