Objective Be able to use angle facts to solve problems in geometry.

FACT A Angles around a point add up to 360º

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

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

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

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

FACT F Vertically opposite angles are equal. aa b b

FACT G Alternate angles are equal a a

FACT G Corresponding Angles are equal b b

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