Respuesta :

Answer:

A

Step-by-step explanation:

3x and x + 30 are vertically opposite angles and are congruent , then

3x = x + 30 ( subtract x from both sides )

2x = 30 ( divide both sides by 2 )

x = 15

Then

∠ A = 3x = 3(15) = 45°

See <A and x+30 are opposite angles .

We know that opposite angles are equal

so

  • 3x=x+30
  • 2x=30
  • x=15

Now

  • <A=3x=45°

Option A is correct