Answer:
0.75+0.75+0.75=2.25 inches
triangles are equal.So add 0.75 three times and write the answer as I mentioned. Also you must do it according to the book.I mean like,you adds it 3 times because triangle is 3 sided and it's a equilateral triangle.
Are you in Grade 8? bcoz me too.
btw I hope this helps you..