Answer:
∠ACD= ∠BAC ( reason: CPCTC)
Given: ∠A is a straight angle. ∠B is a straight angle.
We need to Prove: ∠A≅∠B.
We know straight angles are of measure 180°.
So, ∠A and <B both would be of 180°.
It is given that ∠A and ∠B are straight angles. This means that <u>both angles are of 180°</u> because of the <u>the definition of straight angles</u>. Using <u>the definition of equality</u>, m∠A=m∠B . Finally, ∠A≅∠B by <u>definition of congruent. </u>

1) Since in the USA 8 x 10 ^9 messages are sent every month, that means that approximately 8 billion messages are sent.
2) We can Prime factorize it:
Note that on the right side we've picked only prime numbers. In this case, 2 and 5.
So we can rewrite 8 x 10^9 as prime factors.

3) Hence, the answer is:
Answer:
您能再解釋一下嗎,謝謝
Step-by-step explanation:
Answer:
The maximum temperature will be -10°C, then if T represents the temperature, we can write this as:
T ≤ -10°C
And the minimum temperature will be -25°C, then we must have that:
T ≥ -25°C
if we use both conditions, we will have:
-25°C ≤ T ≤ -10°C
We can write this range:
[-25°C, -10°C]
Where the [] symbols mean that the extremes are possible temperatures.
The length of the range will be:
-10°C - 25°C = 15°C.