A Triangle with Vertices at (X1, Y1), (X2, Y2), and (X3

question 389

Multiple Choice

A triangle with vertices at (x1, y1) , (x2, y2) , and (x3, y3) has area equal to the absolute value of D, where $$D = \frac { 1 } { 2 } \left| \begin{array} { l l l } x _ { 1 } & y _ { 1 } & 1 \\x _ { 2 } & y _ { 2 } & 1 \\x _ { 3 } & y _ { 3 } & 1\end{array} \right|$$ Find the area of the triangle having vertices at P, Q, and R.
-P(0, 5) , Q(5, 8) , R(7, 4)

• A) 13
• B) 2
• C) 26
• D) 0

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Definitions:

Cognitive Operations

Mental processes that involve the manipulation and transformation of information in problem solving and decision making.

Field-Independent

A cognitive style where individuals tend to be more analytical, succeeding in tasks that require breaking down a larger picture into its component parts without being influenced by the context.

Embedded Figures

Involves finding a simple shape or figure hidden within a complex background, testing perceptual organization and the ability to distinguish foreground from background.

External Referents

Refers to objects, events, or entities outside of a person's mind that are referred to by linguistic expressions or symbols.