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the diagram shows figures rotated about point p. text alternative: wher…

Question

the diagram shows figures rotated about point p. text alternative: where will l be if it is rotated 90 degrees counterclockwise about p? choose the correct answer. options: a) c, b) d, c) j, d) m

Explanation:

Step1: Recall Rotation Rules

A 90° counterclockwise rotation about a point \( P \) means we use the rule: for a point \((x,y)\) relative to \( P \) (treated as the origin), the new coordinates are \((-y,x)\). But visually, we can look at the position of \( L \) relative to \( P \).

Step2: Analyze Position of \( L \)

Point \( L \) is on the segment \( DC \), below \( P \). When rotating 90° counterclockwise about \( P \), we check the direction. The vector from \( P \) to \( L \) (let's assume \( P \) is the center) – rotating that vector 90° counterclockwise. Looking at the diagram, the position of \( L \) when rotated 90° counterclockwise should map to \( M \)? Wait, no, wait. Wait, let's re - examine. Wait, the points: \( L \) is at the bottom side ( \( DC \) side). Rotating 90° counterclockwise about \( P \): let's consider the square - like structure. The distance from \( P \) to \( L \) is the same as from \( P \) to \( M \) or others? Wait, no, let's think of the rotation of the segment \( PL \). If we rotate \( PL \) 90° counterclockwise, the new position should be \( PM \)? Wait, no, maybe I made a mistake. Wait, let's list the points: \( L \) is on \( DC \), \( K \) on \( AD \), \( J \) on \( AB \), \( M \) on \( BC \). Rotating \( L \) 90° counterclockwise about \( P \): the direction from \( P \) to \( L \) is down - right? Wait, no, the diagram is a rhombus with center \( P \). Let's consider the rotation of a point around the center. A 90° counterclockwise rotation: if we have a point at (let's say) (1, - 1) relative to \( P \) (origin), after 90° counterclockwise rotation, it becomes (1,1)? No, the rotation matrix for 90° counterclockwise is \(

$$\begin{pmatrix}0&- 1\\1&0\end{pmatrix}$$

\). So if a point has coordinates \((x,y)\) relative to \( P \), after rotation, it becomes \((-y,x)\). Suppose \( L \) is at (a, - b) (below \( P \)), then after rotation, it becomes (b,a), which would be on the right side (like \( M \) is on \( BC \))? Wait, no, maybe the correct mapping: when we rotate \( L \) 90° counterclockwise about \( P \), the image should be \( M \)? Wait, no, let's check the options. Wait, the options are A) \( C \), B) \( D \), C) \( J \), D) \( M \). Wait, maybe I messed up the direction. Wait, 90° counterclockwise: let's take the segment \( PL \). If we rotate \( PL \) 90° counterclockwise, the new segment should be perpendicular to \( PL \) and in the counterclockwise direction. Alternatively, look at the symmetry. The figure is symmetric about \( P \). The point \( L \) is on the lower side ( \( DC \) ). Rotating 90° counterclockwise: the lower side ( \( DC \) ) when rotated 90° counterclockwise becomes the right side ( \( BC \) ). So the point \( L \) on \( DC \) when rotated 90° counterclockwise should go to \( M \) on \( BC \)? Wait, no, maybe the correct answer is \( M \), which is option D. Wait, let's re - check. Let's consider the position of \( L \): \( L \) is between \( D \) and \( C \). Rotating 90° counterclockwise about \( P \), the vector \( \overrightarrow{PL} \) (from \( P \) to \( L \)) will rotate 90° counterclockwise. So if \( \overrightarrow{PL} \) is in the direction of (let's say) 3 o'clock to 6 o'clock (downward right), rotating 90° counterclockwise would make it go to 12 o'clock to 3 o'clock (upward right), which is the direction of \( \overrightarrow{PM} \). So \( L \) rotated 90° counterclockwise about \( P \) is \( M \).

Answer:

D) \( M \)