Which algebraic expression is a trinomial?

In the proof of the triangle angle sum theorem, you must draw an auxiliary line. which construction must you use to draw this line?

Cass decided to sell game programs for the hockey game. the printing cost was over 20 cents per program with a selling price of 50 cents each. cass sold all but 50 of the programs, and made a profit of $65. how many programs were printed? letting p represent the number of programs printed, set up an equation that describes this situation. then solve your equation for p.

Which statements about these triangles is true