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Which of the following statements must be true?select all that apply.

options B, C, E will be correct according to the given diagram.

Explanation:

Since, according  to the Exterior Angle theorem, In a triangle the sum of any two adjacent interior angles is equal to the exterior angle of the triangle.

And, here  is the exterior angle of the triangle, while , , and  are the interior angles of the triangle.

Thus, according to the theorem,

.

⇒

and

Therefore, options B, C, E are correct.

Step-by-step explanation:

correct answer:

i^31 = -i

5=812a+9+3

step 1: simplify both sides of the equation.

5=812a+9+3

5=(812a)+(9+3)(combine like terms)

5=812a+12

5=812a+12

step 2: flip the equation.

812a+12=5

step 3: subtract 12 from both sides.

812a+12−12=5−12

812a=−7

step 4: divide both sides by 812.

812a /812 = -7/812

a= -1/116

so the answer is

a=   -1/116