The word TRIANGLE is written in the first quadrant (above the X-axis) of a coordinate plane. The mirror image of the above text about the X-axis is A. TRIANGLE written upside-down and reversed left-to-right (both horizontally and vertically flipped) B. TRIANGLE written upside-down but left-to-right order preserved (only vertically flipped) C. TRIANGLE written upside-down with partial reversal D. TRIANGLE written as a horizontal mirror with letters reversed

GATE 2021 · General Aptitude · Mirror Image · medium

Answer: Option B: TRIANGLE with each letter flipped upside-down, left-to-right order preserved — the correct X-axis reflection.

1. Identify the mirror line and its effect: The mirror is the X-axis (horizontal). Reflecting about a horizontal axis changes the y-direction only. So each letter remains at the same horizontal position but flips top-to-bottom (upside down).
2. Determine left-right order of letters: Since x-coordinates are not changed, the sequence T-R-I-A-N-G-L-E remains from left to right. No reversal of word order or letter sequence occurs.
3. Describe the final image: The mirror image is TRIANGLE written with each letter upside-down (vertically inverted) but in the correct left-to-right reading order. This matches option B.