1. The shape of cross-section is a circle.
2. The face parallel to ABCD is EFGH. Since this is a a rectangular shape,
A = L*H = 12*6 = 72 cm^2
3. The cross-section parallel to ABC is DEF with h = 12 ft, b= 5ft (where h is the height and b is the base of a right angled triangle).
Area, A = 1/2 *b*h = 1/2*5*12 =30 ft^2
4. Plane BDHF is a rectangle shape whose length is the diagonal of ABCD.
Diagonal BD = sqrt (AB^2+BD^2) = sqrt (8^2+7^2) = 10.63 cm.
Perimeter, P = 2(BD+DH) = 2(10.63+6) = 33.26 cm
Statement 1 is true.
-Hope this helps, have a nice day! :)
Melanie: 15 years old
Kevin: 5 years old
Assume Kevin's present age is x.
That means that 3 years ago, his age would be x - 3.
Melanie's age would be 6(x - 3).
Same thing for 5 years into the future:
Kevin's age would be x + 5.
Melanie's age would be 2(x + 5).
The two equations we have here are:

By subtracting both equations, we are simplified to:
8 = -4x + 28
By solving the equation, we get x = 5.
That means that Kevin's current age is 5 years old.
Melanie's age could be calculated by substituting Kevins'.
6(x - 3) --> 6(5 - 3) --> 12
Since that was 3 years ago, you need to add 3 to 12 to get her current age.
12 + 3 = 15
Melanie's current age is 15 years old.
You would need to know the dimensions of the pyramid and wether it was triangle or square bottomed
Answer:
69
Step-by-step explanation: