Question

An intersection is a point where two or more lines/curves meet or cross. How many intersections are there in the figure given below? 

 

Hint:

When counting elements in a complex figure, it's best to categorize them. For intersections, you can group them by location (center, inner shape, outer shape) or by the type of lines creating them (line-line, line-curve). Mark points on the diagram as you count to avoid errors.

Answer 1

Correct Answer: 17

Step 1: Understanding the Concept: 
The task is to count all the distinct points in the given figure where lines or curves intersect (meet or cross each other). A systematic approach is needed to avoid double-counting or missing any intersection points. 
Step 2: Detailed Explanation: 
We can break down the figure into its components and count the intersections for each part and between parts. Let's count in a structured way, from the center outwards. 


Central Intersection: There is one point in the very center where the two main diagonal lines cross. 
{Count = 1} 
Vertices of the Inner Square: The tilted inner square has four vertices where its sides meet. 
{Count = 4} 
Vertices of the Outer Square: The main outer square has four vertices. These are also points where the curved arcs meet the square. 
{Count = 4} 
Diagonals crossing the Inner Square: The two long diagonal lines cross the four sides of the inner tilted square at four distinct points. 
{Count = 4} 
Curves meeting the Outer Square sides: The four curved arcs start and end at the midpoints of the sides of the outer square. These four meeting points are intersections. 
{Count = 4} 
Step 3: Final Answer: 
To find the total number of intersections, we sum the counts from each group: 
\[ \text{Total Intersections} = 1 (\text{center}) + 4 (\text{inner vertices}) + 4 (\text{outer vertices}) + 4 (\text{diagonal crossings}) + 4 (\text{arc endpoints}) \] The question's definition might group some of these. Let's re-evaluate based on the provided answer key. A common way to count for this specific puzzle is: 

Central intersection point: 1 
Vertices of the outer square: 4 
Vertices of the inner square: 4 
Intersections of the diagonals with the inner square's sides: 4 
Intersections of the curved lines with the outer square's sides: 4 
Summing these gives: \(1 + 4 + 4 + 4 + 4 = 17\). This appears to be the intended method. \[ \text{Total Intersections} = 1 + 4 + 4 + 4 + 4 = 17 \] The total number of intersections in the figure is 17.