Answer: B
Step-by-step explanation:
Answer:
6 cm²
Step-by-step explanation:
Since 3 side lengths are given, I assume that this figure is a triangle. The area of a triangle can be determined by using hero's formula.

⇒ s = Perimeter/2
⇒ a, b, and c = side lenths of triangle
<u>Replacing a, b, and c as the given side lengths:</u>

<u>Determining the perimeter of the triangle:</u>



<u>Determining the half of perimeter:</u>



<u>Replacing the value of "s" in the formula:</u>

<u>Evaluating the area:</u>




Answer: 0.8 or 80%
Step-by-step explanation:
First find the total number of marbles:
10 + 15 + 25 = 50 marbles total
To find the number of marbles that are not black:
15 + 25 = 40 marbles that are not black
Set up ratio:
= 0.8 or 80%