Informal letter writing in English

How much dextrose 70% must be mixed with dextrose 5% to prepare 1,000 ml of dextrose 20%?

In triangle △abc, ∠abc=90°, bh is an altitude. find the missing lengths. ah=4 and hc=1, find bh.

Ineed your ! i was to turn this into pond first thing i gotta do is outline the inside with this plastic how big should i cut the plastic the height: 10 1/2” the length: 40” the width: 12” me !