An equilateral triangle has an apothem of 5 cm. Find the perimeter of the triangle to the nearest centimeter.
1 answer:
The apothem is the distance from the center to the midpoint of one of the sides of a regular polygon. You can make a right triangle with the apothem, the line from the midpoint to the corner and the line from the center to the corner. An equilateral triangle has 60 degree angles (180/3). The right triangle has half of one of those angles so 30 degrees. Now we have a 30-60-90 triangle where the short leg is 5cm. The long leg, which is also half of one side of the triangle is thus 
. A whole side of the triangle is 
. Multiply that by 3 to get the perimeter of <span>
.</span>
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Answer:
B. 12.5%
Step-by-step explanation:
Add all the hours together to get 20. We make the assumption that 20 is 100% since it is our output value. We next represent the value we seek with x. From step 1, it follows that 100%=20. In the same vein, x%=2.5.This gives us a pair of simple equations:
100%=20(1)
x%=2.5(2)
By simply dividing equation 1 by equation 2 and taking note of the fact that both the LHS (left hand side) of both equations have the same unit (%); we have
=
Taking the inverse (or reciprocal) of both sides gives us this:
>> x=12.5\%
Therefore, 2.5 is 12.5% of 20.