On a math test, Sally got 30 out of 35 problems correct. What percent of the problems were incorrect?
1 answer:
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Answer:
one side =
Step-by-step explanation:
if you draw an octagon on a piece of paper, you can draw a square around it, you should be able to see a diagram of this attached, ignore the 6.
Let's say TP = a
since it's a regular octagon, TP = HT
and using the Pythagoras Theorem, we know a² + b² = c² and thus:
√(AT² + HA²) = HT
and since AT = HA which we will call x, the equation becomes:
√(2x²) = HT = a
rearrange the equation to solve for x and you get:
2x² = a²
x² =
x =
which, if you rationalise the denominator, you get:
x =
