Answer:
you forgot the question
Step-by-step explanation:
Answer:
Use Heron's formula; see below.
Step-by-step explanation:
Use Heron's formula.
Let the sides of the triangle have lengths a, b, and c.


Example:
A triangle has side lengths 3, 4, and 5 units.
Find the area of the triangle.








Multiply x<span> and </span>3
<span>Multiply x and 1</span>
<span>The x just gets copied along.</span>
<span>The answer is x</span>
x
<span>3*x evaluates to 3x</span>
Because of the minus sign
<span>3x becomes - 3x</span>
<span>The answer is -3x</span>
<span>Multiply y and 2</span>
<span>Multiply y and 1</span>
<span>The y just gets copied along.</span>
<span>The answer is y</span>
y
<span>2*y evaluates to 2y</span>
<span>-3*x-2*y evaluates to -3x-2y</span>
<span>The answer is -3x-2y-2</span>
<span>-3*x-2*y-2 evaluates to <span>-3x-2y-2</span></span>
<span><span>so the first one is right</span></span>
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A and c are true ! I hope this helps