Which of the triangles in the diagram are congruent?

A.
triangle 1, triangle 2, and triangle 3
B.
triangle 1, triangle 3, and triangle 4
C.
triangle 3, triangle 4, and triangle 5
D.
triangle 3 and triangle 5
E.
triangle 2 and triangle 5

[10 points, algebra 2-simplifying complex fractions]according to my answer key the restrictions are -1 and 4. but why not positive 1?

Express the following as a function of a single angle. cos(60) cos(-20) - sin(60) sin(-20)

Plz answer asap! i will reward brainliest and 12 points for these three questions!take notice: these three questions are completely different! 1) what is the percentage of sugar in the syrup made of 10 kg of water and 4 kg of suugar? 2) what was the original price if after 10% discount it became $450? 3) at first a price was decreased by 12%, then it was disounted again by an additional 5%. what is the percent of the total discount? , and remeber i will award brainliest and 12 points!