the surface area of a cone is 436 and the radius of the base is 7 what is the slant height of the cone

Umm.. just started this 2day and its not on my notes(p′︵‵。)

Ineed asap graph the system of equations 2x+y=5; 14+7y=35

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