Answer:
option D. DE = 11
Step-by-step explanation:
The line DF is equivalent in length to the blue line,
(x + 7) + 7 = 4x + 2
Solve:
x + 14 = 4x + 2
subtract 14 from both sided to get x alone,
x + 14 - 14 = 4x + 2 - 14
x = 4x - 12
subtract 4x from both sided,
x - 4x = 4x - 4x - 12
-3x = -12
divided both sides by -3,
-3x / 3 = -12 / -3
x = 4
Plug in x into DE equation:
x + 7: (4) + 7 = 11
Here is another example of solving for x, give it a try! : brainly.com/question/11979991
Answer:
Part a) Rectangle
Part b) Triangle
Step-by-step explanation:
Part A) A cross section of the rectangular pyramid is cut with a plane parallel to the base. What is the name of the shape created by the cross section?
we know that
When a geometric plane slices any right pyramid so that the cut is parallel to the plane of the base, the cross section will have the same shape (but not the same size) as the base, So, in the case of a right rectangular pyramid, the cross section is a rectangle
Part b) If a cross section of the rectangular pyramid is cut perpendicular to the base, passing through the top vertex, what would be the shape of the resulting cross section?
we know that
Cross sections perpendicular to the base and through the vertex will be triangles
Answer:
A
Step-by-step explanation:
The projection of vector B on unit vector a is
(B•a)a
av(unit vector of v)= 1/√2(-1,1)
u•av= 1/√2 × (-5+7)= √2
(u•av)av= √2 × 1/√2(-1,1)= (-1,1)
