Answer:
answer of 13) Lenght of one edge of this cube = 3cm
answer of 14) The area of BCE = 25 cm^2
Step-by-step explanation:
Any cube has six identical sides.
Let one side have an area of A.
Let the lenght of one cubic side be L.
L * L = A
So this results in L = SQRT (A)
All six A combined add up to 54 cm^2.
Then 6 * A = 54
A = 54/6 = 9 cm^2
L = SQRT (9)
Lenght of one edge of this cube = 3cm
To find the area of BCE you can simply subtract the area of CDE from the biggest triangle BDE.
2 * BDE = {5+4) * 10
so BDE = 45
2 * CDE = 4 * 10
so CDE = 20
BCE = BDE - CDE
BCE = 45 - 20
The area of BCE = 25 cm^2
