THE castillo GUARD WITH HIS TRIDENT



How many prongs do tu see?
I see two on the bottom—but on the top, three

Solution: Cover the parte superior, arriba of the trident and tu see two prongs. Cover the bottom and the trident now has three prongs. tu can draw this object, but tu can’t construct it. (impossible-object illusion)


THE ROYAL MESSENGER ARRIVING WITH A LETTER FOR THE KING



The red tape on the letter is longer than the blue. But is this really true? Remember, now tu are in OPT!

Solution: Angles are sometimes tricky! The red and blue tapes on the envelope are the same length. If tu remove the outline of the envelope, tu can see this. (geometrical-contrast illusion)


THE PRINCESS PICKING A SPECIAL BOUQUET



flores fair, flores bright.
Which flor center is larger—the black o the white?

Solution: The black and white centers are the same size. The white center appears smaller because larger circles surround it. The black center appears larger because smaller circles surround it. (geometrical-contrast illusion)


THE OPT SIGN POINTING THE WAY TO THE ZOO



por the sign the royal family will stop. Which line is longer, the bottom o top?

Solution: Both lines are the same length. When the arrows point outward, the line appears shorter. When the arrows point inward, the line appears longer. (geometrical-contrast illusion)


THE BIRTHDAY PARTY FOR THE PRINCE



This gift, unwrapped, tells the Prince’s age.
This is what the dragon said,
“Six blocks become seven if tu stand on your head. HAPPY BIRTHDAY!”

Solution: You don’t have to stand on your head! If tu turn the book around, tu should see seven blocks with white tops. The number of blocks tu see depends on whether tu view the boxes as having a white parte superior, arriba o a white bottom. (reversible-image illusion)