Which of the triangles has the greatest area? Can you also please explain so I can do it by my self with a similar one?

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

(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.

George writes the mixed number as sum and uses the distributive property 1/2.-2/5=1/2-2+2/5=1/2