Which of these are congruent?

linear angles

vertical angles

consecutive angles

all of these

If points A, B, and C are on a circle and AB is a diameter, which of the following is true?

m∠ACB ＝ 90°.

Arc AB is a semicircle.

ACB is an inscribed angle.

All of these are correct.

What is the sum of the interior angles in an octagon?

360°

6(180°) ＝ 1080°

8(180°) ＝ 1440°

10(180°) ＝ 1800°

A regular dodecagon has 12 angles, each of which is 150°. What is the sum of these angles?

1800°

12(150°)

(12 – 2)180°

All of these are correct.