Answer:
<em>Answer</em><em> </em><em>is</em><em> </em><em>-6</em>
Step-by-step explanation:

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<span>This is an isosceles triangle. If each side is 1, we can find the hypotenuse using the Pythagorean theorem.
a^2 + b^2 = c^2
1^2 + 1^2 = c^2
1 + 1 = c^2
2 = c^2
root 2 = c
Thus, the answer is root 2.
Hope this helps :)</span>
For the first 60 positive integers, a = 1, n = 60, l = 60.
Sn = n/2(a + l)
s = 60/2(1 + 60) = 30(61)
For the next 60 positive integer, a = 61, n = 60, l = 120
Sum = 60/2(61 + 120) = 30(61 + 120) = 30(61) + 30(120) = s + 3600
Sum of first 120 positive integers = s + s + 3600 = 2s + 3600
The formula for the circumference of a circle = 2 x radius x pi
The radius is given as 21 cm and pi = 3.142
Circumference = 2 x 21 x 3.142 = 131.964 cm