Which one of the answer figure will complete the sequence of the three problem figures ?
Show Hint
Each triangle is the previous one turned by 90 degrees anticlockwise, and the inner line shifts to the next vertex. Apply the same two changes once more.
Step 1: The three given figures are the same triangle with one inner line drawn from a vertex to a point on the opposite side. In the first figure the apex points right, in the second it points up and in the third it points left, so every figure is the previous one turned by 90 degrees anticlockwise. Step 2: The fourth figure must therefore have its apex pointing down, with the flat side on top. Step 3: Track the inner line. In figure 1 it runs from the top-left vertex to a point on the opposite (lower) side lying near the bottom-left vertex. In figure 2 it runs from the apex to the base at a point near the left vertex. In figure 3 it runs from the top-right vertex to the opposite side at a point near the apex. The whole drawing is simply being rotated. Step 4: Turning figure 3 by another 90 degrees anticlockwise gives a triangle pointing down, with the inner line starting at the top-right vertex and ending on the left slanted side close to the top-left vertex. Step 5: Option 3 is the only figure with this arrangement. Option 1 ends the line much lower on the left side, option 2 draws the line to the bottom apex, and option 4 starts the line from the top-left vertex. Answer: (3) the figure shown in option 3
