The amount of material needed by Marta to make the flag is;
square inch.
The total cost of making the flag is;
dollar.
Given
Marta is making a flag with the given dimensions.
The perimeter of the flag is 100 inches.
Let us consider that the flag has a triangular shape.
<h3>Hero's formula;</h3>
According to the Hero's formula;
The area of the triangle is given by;
![\rm Area =\sqrt{s(s-a)(s-b)(s-c)}](https://tex.z-dn.net/?f=%5Crm%20Area%20%3D%5Csqrt%7Bs%28s-a%29%28s-b%29%28s-c%29%7D)
Where, s is the semi perimeter and a, b, and c are the sides of the triangle.
Semi perimeter s = P/2,
Since the perimeter of the flag is 100 inches.
![\rm S=\dfrac{100}{2}\\\\S=50](https://tex.z-dn.net/?f=%5Crm%20S%3D%5Cdfrac%7B100%7D%7B2%7D%5C%5C%5C%5CS%3D50)
The dimensions of triangular shape are
.
Then,
The area of the triangular flag becomes;
![\rm Area =\sqrt{s(s-a)(s-b)(s-c)}\\\\\rm Area =\sqrt{50(50-d_1)(50-d_2)(50-d_3)}](https://tex.z-dn.net/?f=%5Crm%20Area%20%3D%5Csqrt%7Bs%28s-a%29%28s-b%29%28s-c%29%7D%5C%5C%5C%5C%5Crm%20Area%20%3D%5Csqrt%7B50%2850-d_1%29%2850-d_2%29%2850-d_3%29%7D)
So the amount of material needed to make the flag is;
![\rm Area =\sqrt{50(50-d_1)(50-d_2)(50-d_3)}](https://tex.z-dn.net/?f=%5Crm%20Area%20%3D%5Csqrt%7B50%2850-d_1%29%2850-d_2%29%2850-d_3%29%7D)
Therefore,
The cost of material = C = $0.15 per square inch
So the total cost in making the flag will be;
.
Hence, The amount of material needed by Marta to make the flag is
.
To know more about Hero's formula click the link given below.
brainly.com/question/24399817