ISOSCELES TRIANGLE • E-FREE TRANSLATION.COM • Definition of Isosceles triangle

... beginning with straight lines. Having continued this examination for about half an hour, we proceeded to enter into particulars respecting triangles; and having discoursed on the difference between isosceles triangles and scalene triangles, I observed that an acute isosceles triangle had all its angles acute, and proceeded to observe that a right-angled scalene triangle had all its angles acute. The children immediately began to laugh, for which I was at a loss to account, and told them of the impropriety of laughing at me. One ...

— The Infant System - For Developing the Intellectual and Moral Powers of all Children, - from One to Seven years of Age • Samuel Wilderspin