Answer:
Its when you add angles together
Its when two angles are congruent
Step-by-step explanation:
I suspect you meant
"How many numbers between 1 and 100 (inclusive) are divisible by 10 or 7?"
• Count the multiples of 10:
⌊100/10⌋ = ⌊10⌋ = 10
• Count the multiples of 7:
⌊100/7⌋ ≈ ⌊14.2857⌋ = 14
• Count the multiples of the LCM of 7 and 10. These numbers are coprime, so LCM(7, 10) = 7•10 = 70, and
⌊100/70⌋ ≈ ⌊1.42857⌋ = 1
(where ⌊<em>x</em>⌋ denotes the "floor" of <em>x</em>, meaning the largest integer that is smaller than <em>x</em>)
Then using the inclusion/exclusion principle, there are
10 + 14 - 1 = 23
numbers in the range 1-100 that are divisible by 10 or 7. In other words, add up the multiples of both 10 and 7, then subtract the common multiples, which are multiples of the LCM.
You can use SAS since you know one pair of sides are congruent and AC splits them so those must make those sides equal. And since those sides, DC and BC, are congruent, the angles must be as well. You can use numbers to prove the angles of D and B or just use that when 2 sides and an angle are congruent, the 3rd side must be congruent.
