Vertex Angles

CONCEPTS

Vertex angles

• Opposite angles are = (∠1 = ∠4, ∠2 = ∠3, ∠6 = ∠7, ∠5 = ∠8

PRACTICE PROBLEMS

Question 1 The intersection of line l & m forms the 4 angles ∠ A, ∠ B, ∠ C, ∠ D. The measure of ∠ B is 3 ½ times the measure of ∠ A. What is the value of ∠ A?

-- Answer -- 40°

∠ A + ∠ B = 180°

∠ A = 3.5 ∠ A

∠ A = 40°

ACT PRACTICE PROBLEMS