Answer:
Option 1st is correct
[tex]3 \cdot (\frac{1}{2} \cdot 10 \cdot 5)=x[/tex]
Step-by-step explanation:
Area of the triangle is given by:
[tex]A = \frac{1}{2}bh[/tex]
where,
A is the area of the triangle
b is the base and
h is the height of the triangle.
As per the statement:
For a project, you need to make three triangles out of cardboard.
Each triangle has a height of 5 inches and a base of 10 inches
⇒b = 10 inches and h = 5 inches
[tex]\text{Area of each triangle} = \frac{1}{2} \cdot 10 \cdot 5[/tex]
Since, you need to make three triangles out of cardboard
⇒[tex]\text{Area of 3 triangle}(x) =3 \cdot (\frac{1}{2} \cdot 10 \cdot 5)[/tex]
Therefore, an equation can you use to solve for the total amount of cardboard you will need is,
[tex]3 \cdot (\frac{1}{2} \cdot 10 \cdot 5)=x[/tex]
