Scientists often blank and blank to them interpret complex ideas. i need answer !

Suppose the radius of a circle is 16. what issuppose the radius of a circle is 16. what is its circumference its circumference

Find the number of real number solutions for the equation. x2 + 5x + 7 = 0 0 cannot be determined 1 2

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