None, since there is no such measure as an angstrong. The measurement is named after the Swedish physicist Angstrom and you should have the common decency to make the effort to spell the name correctly. 70 Angstrom = 7*10-9 metres or 7 billionths of a metre.
We know that one Angstrom = 1×10−10 meters and 1 meter=1000 mm so 1x10-10 meters x 103 mm/ meter = 10-7 mm
From the related links: between about 10 nanometers (most energetic Extreme Ultraviolet) to about 300 nanometers (least energetic Near Ultraviolet). Visible violet light is about 400 nanometers.