What are these in scientific notations?

Atriangle with all sides of equal length is a/an triangle. a. right b. scalene c. equilateral d. isosceles

An ulcer medication has 300 milligrams in 2 tablets. how many milligrams are in 3 tablets?

In the figure below, ∠dec ≅ ∠dce, ∠b ≅ ∠f, and segment df is congruent to segment bd. point c is the point of intersection between segment ag and segment bd, while point e is the point of intersection between segment ag and segment df. the figure shows a polygon comprised of three triangles, abc, dec, and gfe. prove δabc ≅ δgfe.