Answer:
The area of an octagon whose perimeter is 120 cm is 1086.4 
Step-by-step explanation:
An octagon is a polygon with eight sides. If the lengths of all the sides and the measurement of all the angles are equal, the octagon is called a regular octagon.
There is a predefined set of formulas for the calculation of perimeter, and area of a regular octagon.
The perimeter of an Octagon is given by

and the area of an Octagon is given by

We know that the perimeter is 120 cm, solving for side length (a) in the perimeter formula we get

Now, we calculate the area

Answer:
The answer is D) 60
Step-by-step explanation:
If a coral reef grows at a steady rate every week, then to find how much it grows in 12 weeks, we need to multiply the growth rate by 12 weeks. Also, since we want our answer in centimeters, we can change the growth rate to centimeters. 0.15m = 15cm
15cm * 12 = 180cm
The coral reef will grow 180cm in 12 weeks.
Answer:
x =120
60,60,120,120
Step-by-step explanation:
The sum of the angles is 360
x + x+ 1/2x + 1/2x = 360
Combine like terms
3x = 360
Divide each side by 3
3x/3 =360/3
x =120
The 4 angles are 120, 120,60,60
From least to greatest
60,60,120,120