The measure of an exterior angle of a triangle is equal to the sum of the measures of the two non-adjacent interior angles of the triangle.
m∠4=m∠1+m∠2m∠4=m∠1+m∠2
Proof:
Given: ΔPQRΔPQR
To Prove: m∠4=m∠1+m∠2m∠4=m∠1+m∠2
StatementReason1ΔPQRΔPQR is a triangleGiven2m∠1+m∠2+m∠3=180°m∠1+m∠2+m∠3=180°Triangle Sum Theorem3∠3∠3 and ∠4∠4 form a linear pairDefinition of linear pair.4∠3∠3 and ∠4∠4 are supplementaryIf two angles form a linear pair, they are supplementary.5m∠3+m∠4=180°m∠3+m∠4=180°Definition of supplementary angles.6m∠3+m∠4=m∠1+m∠2+m∠3m∠3+m∠4=m∠1+m∠2+m∠3Statements 2, 5 and Substitution Property.7m∠4=m∠1+m∠2m∠4=m∠1+m∠2Subtraction Property. im 99.9 perecent sure this is right bc im only in middle school but hope it helps
Answer:
.
Reference angle is 
Step-by-step explanation:
Given the value of x. we have to find the correct value of cosx.
Now, we have to find the exact value of 
Now, we have to find the reference angle of .
Since the angle lies in second quadrant, the reference angle formula is
Reference angle= 
.
=
Answer:
23
Step-by-step explanation:
I don't understand this question, can you maybe reword it or make it easier to understand? There's no grammar so I can't understand.
