We need to make a scale between blueprint and actual size. The trick in this question is to understand that the scale for the areas and the scale for the lengths are different.
Scale for area is given in the question as
1 unit on blueprint = 900 units in actual.
As the dining room is given to be rectangular we can find the scale for lengths by taking square root of scale for area.
√1 unit on blueprint = √900 units in actual
Therefore, scale for length= 1:30
Thus, by using the scale we can calculate actual length corresponding to 4 inches on blueprint by multiplying 4 with scale
4 inches×1/30=120inches
Answer = 120 inches
Find an equation of the plane that contains the points p(5,−1,1),q(9,1,5),and r(8,−6,0)p(5,−1,1),q(9,1,5),and r(8,−6,0).
topjm [15]
Given plane passes through:
p(5,-1,1), q(9,1,5), r(8,-6,0)
We need to find a plane that is parallel to the plane through all three points, we form the vectors of any two sides of the triangle pqr:
pq=p-q=<5-9,-1-1,1-5>=<-4,-2,-4>
pr=p-r=<5-8,-1-6,1-0>=<-3,5,1>
The vector product pq x pr gives a vector perpendicular to both pq and pr. This vector is the normal vector of a plane passing through all three points
pq x pr
=
i j k
-4 -2 -4
-3 5 1
=<-2+20,12+4,-20-6>
=<18,16,-26>
Since the length of the normal vector does not change the direction, we simplify the normal vector as
N = <9,8,-13>
The required plane must pass through all three points.
We know that the normal vector is perpendicular to the plane through the three points, so we just need to make sure the plane passes through one of the three points, say q(9,1,5).
The equation of the required plane is therefore
Π : 9(x-9)+8(y-1)-13(z-5)=0
expand and simplify, we get the equation
Π : 9x+8y-13z=24
Check to see that the plane passes through all three points:
at p: 9(5)+8(-1)-13(1)=45-8-13=24
at q: 9(9)+8(1)-13(5)=81+9-65=24
at r: 9(8)+8(-6)-13(0)=72-48-0=24
So plane passes through all three points, as required.
Answer:
The answer is C
2.640 and 10,560
Step-by-step explanation:
264 * 410 = (264 * 400) + (264 * 10) = 105,600 + 2640 = 2.640 and 10,560
