Marks' first lessons in geometry / In two parts. Objectively presented, and designed for the use of primary classes in grammar schools, academies, etc.

by Bernhard Marks

What kind on account of its equal sides?

Then it is called an obtuse-angled isosceles triangle.

Name one other obtuse-angled isosceles triangle.

What kind of a triangle is Fig. 6 on account of the angle q p r?

What kind on account of its equal sides?

Then it is called a right-angled isosceles triangle.

Name one other right-angled isosceles triangle.

Why is Fig. 12 a right-angled triangle? Why isosceles?

EQUILATERAL TRIANGLES.

Which of the isosceles triangles has all its three sides equal to each other?