This document outlines several key facts about angles and triangles: Fact A states that angles around a point add up to 360 degrees. Fact B and C say that angles on a straight line and in a triangle respectively add up to 180 degrees. Fact D notes that the base angles of an isosceles triangle are equal. Fact E gives the angle measure of an equilateral triangle as 60 degrees. Facts F through H cover properties of equal, alternate, corresponding, and allied angles.

1. FACT A Angles around a point add up to 360 º

2. FACT B Angles on a straight line add up to 180 º

3. FACT C Angles in a triangle add up to 180 º a b c a + b + c = 180º

4. FACT D The base angles in an isosceles triangle are equal.

5. FACT E Each angle in an equilateral triangle is 60 º 60 º 60 º 60 º

6. FACT F Vertically opposite angles are equal. a a b b

7. FACT G Alternate angles are equal a a

8. FACT G Corresponding Angles are equal b b

9. FACT H Allied angles add up to 180 º. x y x + y = 180 º