A funny and pun-filled retelling of “The Sword and Stone” that introduces readers to mathematical angles.

King Arthur has hidden his sword, Edgecalibur and issued a challenge to the knights. The first knight to find the sword will be the next king. Can Sir Cumference and Lady Di point Radius's best friend, Vertex in the right direction? Will Vertex's sharp thinking give him the edge?

Join Sir Cumference, Lady Di of Ameter, and their son, Radius, in this new adventure where they race to help Vertex find the sword and discover the secrets of cubes, pyramids, cylinders, and cones.


一首有趣且充滿雙關語的“劍與石”重述，向讀者介紹數學角度。

亞瑟王隱藏了他的劍，Edgecalibur並向騎士發出挑戰。 找到劍的第一位騎士將成為下一任國王。 Cumference爵士和Lady Di能否指出Radius最好的朋友Vertex正朝著正確的方向前進？ Vertex的敏銳思維會給他帶來優勢嗎？

加入Ame的Lady Cumference和他們的兒子Radius，參加這次新的冒險活動，他們將幫助Vertex找到劍並發現立方體，金字塔，圓柱體和錐體的秘密。

（文字整理/徐琍沂&劉世明）