Find the sum or difference -80+77

An appliance store sells lamps at $95.00 for two. a department store sells similar lamps at 5 for $250.00. which store sells at a better rate

The square pyramid has a volume of 441 cubic inches. what is the value of x? 1/7x is the height x is the base

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