Answer:
[tex]\begin{gathered} \text{ a. Yes, a triangle can be formed.} \\ \text{ b. Yes, a triangle can be formed.} \\ \text{ c. Yes, a triangle can be formed.} \\ \text{ d. No, a triangle cannot be formed.} \\ \text{ e. No, a triangle cannot be formed.} \end{gathered}[/tex]Step-by-step explanation:
To determine if three given sides form a triangle, these sides have to comply with the following formulas:
[tex]\begin{gathered} a+b>c \\ a+c>b \\ b+c>a \\ \text{where,} \\ a,b\text{ and c are the given sides} \end{gathered}[/tex]Therefore,
a) Yes, it is an equilateral triangle.
b)
[tex]\begin{gathered} 180>45 \\ 135>90 \\ 135>90 \\ \text{ These sides can create a triangle.} \end{gathered}[/tex]c)
[tex]\begin{gathered} 70>50 \\ 80>40 \\ 90>30 \\ \text{ These sides can create a triangle.} \end{gathered}[/tex]d)
[tex]\begin{gathered} 135>45 \\ 135>45 \\ 90>90\text{ }\rightarrow\text{ FALSE} \\ \text{ These sides cannot create a triangle.} \end{gathered}[/tex]e)
[tex]\begin{gathered} 150>30 \\ 150>30 \\ 60>120\text{ }\rightarrow\text{ FALSE} \\ \text{ These sides cannot create a triangle.} \end{gathered}[/tex]