An isosceles triangle is a triangle with two congruent sides and congruent base angles. congruent means equal. No matter which direction the triangle's apex, or peak, points, it's an isosceles triangle if two of its sides are congruent.
Uses of talc: Talc is used in a wide variety of products that we see every day. It is an important ingredient in rubber, a filler and whitener in paint, a filler and brightening agent in high-quality papers, and a primary ingredient in many types of cosmetics.
For extra credit to impress your teacher: the mineral talc is also used as a filler in colored pencils and crayons! Serpentine(blues/blue-greens), hematite(red, gray, and brown), limonite(red and yellow ocher) mica(silver and gold), tremolite(greens) are some other minerals used as pigments in colored pencils.