Step-by-step explanation:
Two straightener angle are ∠1 and ∠2 , and also a number of straightener angle is 180°. We can make the equation into :
∠1 + ∠2 = 180°
KNOWN ∠2 = 115°
Prove that ∠1 = 65°
Using the equation before, to find ∠1
∠1 + ∠2 = 180°
∠1 +115° = 180°
∠1 = 180° - 115°
∠1 = 65° Proved
