Answer:
D
Step-by-step explanation:
Lateral SA = area of the 4 triangles
Formula to be used :-
Area (triangle) = 1/2bh
=> 4 x 1/2 x 9 x 12
=> 108 x 2
=> 216 cm²
Total SA = LSA + area of the square
Formula to be used :-
Area (square) = side length x side length
=> 216 + 9 x 9
=> 216 + 81
=> 297 cm²
<u>The correct option is (D).</u>
21 is the opposite of -21
Answer: V = 8x^3-80x^3 +200x
Domain 0<x<5
Step-by-step explanation:
Dimension of cardboard = 10 by 10
Let the length of box = 10-2x
Let the width of box = 10 - 2x
Let the height of box be =x
Volume = l×w×h
V = (10-2x)×(10-2x)×x
V= 100 - 40x +42 × x
V= 8x^3 -80x^2 +200x
Step-by-step explanation:

Answer:
D. The area of the triangle is 9 square feet, because the area of the rectangle is 18 square feet.
Step-by-step explanation: