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 [tex]\widehat {CB}[/tex] at the center
m∠CAB = The angle subtended by arc [tex]\widehat{CB}[/tex] at the circumference of the circle
Therefore;
Which gives;
m∠COB = 2 × 60° = 120°
m∠COB = [tex]m_{\widehat{CB}}[/tex] = 120°
Learn more about other circle theorems here:
https://brainly.com/question/16879446
