For fabric at least 10 cm wider than half the chest measurement, 2 lengths + 1 sleeve length + 100 cm. For fabric at least 10 cm wider than 1/4 chest measurement: 4 lengths + 1 sleeve length + 200 cm. These are rough estimates and should give you plenty of fabric for a basic shirt or blouse. Add more for gathering, design features like bias cuts, pleats, etc.
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.
Isosceles Trapezoid. The term isosceles can also refer to the trapezoid, a quadrilateral with a single pair of parallel sides. Much like the triangle, an isosceles trapezoid has a pair of equal non-parallel lines, a single line of reflective symmetry and a pair of matching angles.