Part A
The pattern of squares is 1, 4, 9, ... which is the set of perfect squares
and so on
The 7th figure will have 49 squares because 7^2 = 49
<h3>Answer: 49</h3>
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Part B
Each pattern has one circle per corner (4 circles so far). In addition, there's one circle per unit side to form the perimeter.
- Pattern 1 has 4+4(1) = 8 circles
- Pattern 2 has 4+4(2) = 12 circles
- Pattern 3 has 4+4(3) = 16 circles
The nth term will have 4+4n circles. The first '4' is the number of circles at the corners. The 4n is the circles along the perimeter. If you wanted, 4+4n factors to 4(1+n).
Plug in n = 20 to find the 20th figure has 4+4n = 4+4(20) = 84 circles
<h3>Answer: 84</h3>
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Part C
- Pattern 1 has 1 square + 8 circles = 9 items total
- Pattern 2 has 4 squares + 12 circles = 16 items total
- Pattern 3 has 9 squares + 16 circles = 25 items total
This seems to suggest if the pattern number is odd, then we need an odd number of tiles (square + circular).
Let n be the pattern number. Pattern n needs n^2 square tiles and 4+4n = 4n+4 circular tiles. Overall, n^2+4n+4 tiles are needed.
It turns out that if n is odd, then n^2+4n+4 is always odd. The proof is shown below.
Side note: n^2+4n+4 factors to (n+2)^2
<h3>Answer: B) will always be odd</h3>
Only the third model shows parallel lines cut by a transversal.
We can solve this problem by using some properties that parallel lines cut by a transversal have. First of all, corresponding angles are congruent, and since the angles in figure 1 are corresponding but not congruent, that means that figure one is out.
In addition, in figure two, alternate exterior and interior angles of parallel lines intersected by a transversal are congruent, so since they are not in the picture, that means that this figure is also out.
Figure three is correct because since those are same side interior angles, they need to be supplementary for those to be two parallel lines intersected by a transversal. Since they do, in fact, add up to 180°, that means that the answer is figure three.

<span><span><span>2<span>(2^2)</span></span>(3)</span><span>(2^2)
</span></span><span><span><span>2<span>(2^2)</span></span>(3)</span><span>(2^2)
</span></span><span>=96</span>