Answer: D
Step-by-step explanation:
10 is the missing number.
I velieve u multiply the 3s to cancel eachother out
Answer:
about 8 cm
Step-by-step explanation:
The formula for the area of a regular polygon is ...
A = 1/2Pa . . . . where P is the perimeter and "a" is the apothem, the distance from the center to a side
Filling in your numbers, we have ...
20 cm^2 = (1/2)P(5 cm)
Dividing by the coefficient of P, we find ...
2×(20 cm^2)/(5 cm) = P = 8 cm
The perimeter of the pentagon is about 8 cm.
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<em>Comment on the problem</em>
This calculation makes use of the area formula, as apparently intended. A regular pentagon with an apothem of about 5 cm will have an area of about 90.8 cm^2. The given geometry is impossible, as the pentagon is nearly 10 cm across. It cannot have a perimeter of only 8 cm.
