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505-555 (Easy)|   Geometry|      
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MathRevolution
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A triangle’s area is S=√( ((p-) )(p-) )(p-c)), where a, b and c are th Updated on: 24 Nov 2016, 18:26
Originally posted by MathRevolution on 22 Nov 2016, 01:41.
Last edited by MathRevolution on 24 Nov 2016, 18:26, edited 1 time in total.
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C
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15% (low)

Question Stats:

88% (01:38) correct 13% (01:55) wrong based on 73 sessions

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A triangle’s area is S=\(\sqrt{( p(p-a )(p-b )(p-c))}\), where a, b and c are the three side lengths of the triangle and p=(a+b+c)/2. When a=5, b=6 and c=7, what is the area of the triangle?

A. 4√6 B. 5√6 C. 6√6 D. 7√6 E. 8√6
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C
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A triangle’s area is S=√( ((p-) )(p-) )(p-c)), where a, b and c are th 22 Nov 2016, 07:39
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MathRevolution
A triangle’s area is S=√( ((p-) )(p-) )(p-c)), where a, b and c are the three side lengths of the triangle and p=(a+b+c)/2. When a=5, b=6 and c=7, what is the area of the triangle?

A. 4√6 B. 5√6 C. 6√6 D. 7√6 E. 8√6
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You're missing a few key variables in your Heron's Law formula.
S=√[(p)(p-a)(p-b)(p-c)], where a, b and c are the three side lengths of the triangle and p=(a+b+c)/2
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A triangle’s area is S=√( ((p-) )(p-) )(p-c)), where a, b and c are th 22 Nov 2016, 08:11
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MathRevolution
A triangle’s area is S=√( ((p-) )(p-) )(p-c)), where a, b and c are the three side lengths of the triangle and p=(a+b+c)/2. When a=5, b=6 and c=7, what is the area of the triangle?

A. 4√6 B. 5√6 C. 6√6 D. 7√6 E. 8√6
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Heron's formula:
\(S=\sqrt{p(p-a)(p-b)(p-c)}\) with \(p=\frac{a+b+c}{2}\)

a=5, b=6, c=7 then \(p=\frac{5+6+7}{2}=9\)

\(S=\sqrt{9 \times (9-5) \times (9-6) \times (9-7)}=\sqrt{9 \times 4 \times 3 \times 2}=\sqrt{6^2 \times 6}=6\sqrt{6}\)

The answer is C
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A triangle’s area is S=√( ((p-) )(p-) )(p-c)), where a, b and c are th 24 Nov 2016, 02:46
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==> If you substitute p=(5+6+7)/2=9 into S=\(\sqrt{√(p(p-a)(p-b)(p-c))}\), it becomes S=\(\sqrt{(9*4*3*2)}\)=6√6. Therefore, the answer is C.

Answer: C
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A triangle’s area is S=√( ((p-) )(p-) )(p-c)), where a, b and c are th 27 Oct 2017, 10:36
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Hello Modertors/MathRevolution

The highlighted part of the question stem is incorrect here. It is not possible to get the answer with whats written. Please take and look and correct the same.

Thanking you in advance.

MathRevolution
A triangle’s area is S=\(\sqrt{( ((p-) )(p-) )(p-c))}\), where a, b and c are the three side lengths of the triangle and p=(a+b+c)/2. When a=5, b=6 and c=7, what is the area of the triangle?

A. 4√6 B. 5√6 C. 6√6 D. 7√6 E. 8√6
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