Answer: All sides are 5cm hope this helps...
Answer:
The center of the tetrahedron divides each of the four heights (or medians) in the ratio 1:3 (in an equilateral triangle the corresponding ratio is 1:2). The smaller part is also the radius of the inscribed sphere. Therefore the radius of this sphere is one quarter of the height or 9 in your case.
Answer:
74
Step-by-step explanation:
The mean of any set of numbers is simply the sum of the numbers divided by however many numbers you have. Because of this you can write the following equation
Mean = (sum of numbers)/(number of numbers)
Let's say that the missing test score is called x:
Mean = 80 = (80 + 85 + 73 + 78 + 90 + x)/6
80(6) = 80 + 85 + 73 + 78 + 90 + x
480 = 80 + 85 + 73 + 78 + 90 + x
x = 480 - 80 - 85 - 73 - 78 - 90
x = 74