Step-by-step explanation:
the writing and spacing of the problem description is difficult to understand.
but there is no mystery. look at the examples.
all of them
3×5 = 15 = 16 - 1 = 4² - 1
4×6 = 24 = 25 - 1 = 5² - 1
5×7 = 35 = 36 - 1 = 6² - 1
6×8 = 48 = 49 - 1 = 7² - 1
7×9 = 63 = 64 - 1 = 8² - 1
8×10 = 80 = 81 - 1 = 9² - 1
so, what does this look like ?
(x-1)×(x+1) is always equal to (x² - 1)
6 ÷ 9 or 2/3 are two different ways to write it
Using mathematical reasoning
The area of a regular polygon with given side length and apothem is:
A = <span>½nsr
where
n = number of sides
s = side length
r = apothem
Since decagon has n = 10, hence
A = </span><span>½(10)(20)(10) = 1000 square units (ANSWER)</span><span>
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