I need mentle help spent 69 points

Select all the correct answers. what is 221,000,000,000,000,000,000 expressed in scientific notation?

Type the correct answer in each box. use numerals instead of words. if necessary, use / for the fraction bar. consider the given table.

In the following diagram it is given that dec, ab || dc, ad || eb, and ad is congruent to bc. a)why isn't abc a parallelogram even though it has a pair of parallel sides and a pair of congruent sides b)explain why be must be congruent to bc. further explain what type of triangle this makes triangle abc and what it tells you about angle 1 and angle 2c) finally why must angle 3 be congruent to angle 1? further, explain why we know that angle 3 is congruent to angle 2