Which statements are true? check all that apply. m = 120° m = 60° m∠cob = 2(m∠cab) m∠cob = 120° m∠cob = (m∠cab)

1. m =120° , m =60°¬ (incorrect) ⇒if you are considering a triangle sum of three angles should be 180°. Here sum of two angles is 180. Second thing you can't name the angles of a triangle by small letters.Thirdly two angles can't have same measure.

2.m∠COB = 2(m∠CAB)  ¬ Correct

Consider a triangle COB , AB being the base and O at a certain distance from A.So in this case this possibility is sure to happen.Shown through a diagram

3.m∠COB = 120° ¬ Correct ⇒Consider a triangle COB,∠COB can be obtuse.So we call it obtuse angled triangle.

4.m∠COB = m∠CAB ¬ Correct

To prove this i have given a diagram below.

A relationship between m∠COB and m∠CAB is that they subtend the same

arc on the circumference of the circle wit center at O.

The true statements are;

Reasons:

The possible diagram in the question created with MS Visio is attached.

From circle theorem we have, angle at the center = Twice angle formed at the circumference

m∠COB = The angle subtended by arc at the center

m∠CAB = The angle subtended by arc at the circumference of the circle

Therefore;

Which gives;

m∠COB = 2 × 60° = 120°

m∠COB = = 120°

Learn more about other circle theorems here:

link