Answer:
I think its the 3rd choice
Answer:
Perimeter = 18.7 units
Area = 13.5 units²
Step-by-step explanation:
Perimeter of ADEC = AD + DE + EC + AC
Length of AD = 3 units
By applying Pythagoras theorem in ΔDBE,
DE² = DB² + BE²
DE² = 3² + 3²
DE = √18
DE = 4.24 units
Length of EC = 3 units
By applying Pythagoras theorem in ΔABC,
AC² = AB² + BC²
AC² = 6² + 6²
AC = √72
AC = 8.49 units
Perimeter of ADEC = 3 + 4.24 + 3 + 8.49
= 18.73 units
≈ 18.7 units
Area of ADEC = Area of ΔABC - Area of ΔBDE
Area of ΔABC =
=
= 18 units²
Area of ΔBDE =
=
= 4.5 units²
Area of ADEC = 18 - 4.5
= 13.5 units²
True
-1, -2, -4, -8, ... is the non-arithmetic sequence. It’s geometric as there’s a common ratio of 2.
576 because the triangle in the pyramid would be 216 divided by 2 is 108 since there is 4 triangles to a pyramid you multiply by 4 and that is 432. Then you add the area of the square which is 144 and add that to 432 which makes it 576