What is straight, is part of a line, and has 2 endpoints?

Atriangle with all sides of equal length is a/an triangle. a. right b. scalene c. equilateral d. isosceles

Answer pls man im trying to get out of summer school

(c) the diagram shows the first three shapes of a matchsticks arrangement.first shape = 3second shape = 5third shape = 7given m represents the number of matchstick used to arrange the n'th shape.(i) write a formula to represent the relation between m and n. express m as the subjectof the formula.(ii) 19 matchsticks are used to make the p'th shape. find the value of p.