A fun and educational read the entire family will enjoy.
Plot
Having mastered the knightly right angle, Radius is ready to go on a quest. The neighboring King Lell has disappeared, and none of those seeking him has returned. As Sir D'Grees, his teacher, advises it, Radius' parents, Sir Cumference and Lady Di of Ameter, send the squire to search until he succeeds in rescuing the King. But before he leaves, they have an old family heirloom to give him, a medallion in the shape of a circle with numbers all over it. No one knows what it is for, but perhaps it will help Radius in his journey through angles.
Morality
Bravery and courage are both very strongly upheld and it is considered noble to help your neighbor.
Spiritual Content
Radius is given the family medallion "for luck." Some of the places he goes seem touched by magic, though that is never stated. There are two dragons.
Violence
Radius is warned by many people of the dangers on his path, including "a writhing, screaming fall" and "the dragons' sting". He barely makes it across a bridge before it collapses. He gets chased down a dark tunnel by an unknown menace.
Drug and Alcohol Content
None.
Sexual Content
None.
Crude or Profane Language or Content
None.
Conclusion
Young children will enjoy the fun story of a knight's quest, while older children will learn geometry in a painless and memorable way. The illustrations add color and charm to the story. I highly recommend this whole series as great stories that make it easy to remember geometric terms and concepts.