The associative property of addition is pretty much just any numbers in place of these: a + (b + c) = (a + b) + c. Therefore, your answer would be d) (6 + 1) + 9 = 6 + (1 + 9)
Option B:

Solution:
In the given figure
.
If two triangles are similar, then their corresponding sides and angles are equal.
By CPCTC, in
,
– – – – (1)
– – – – (2)
– – – – (3)
– – – – (4)
– – – – (5)
– – – – (6)
Option A: 
By CPCTC proved in equation (2)
.
Therefore
. Option A is false.
Option B: 
By CPCTC proved in equation (1)
.
Therefore Option B is true.
Option C: 
By CPCTC proved in equation (4)
.
Therefore
. Option C is false.
Option D: 
By CPCTC proved in equation (5)
.
Therefore
. Option D is false.
Hence Option B is the correct answer.

Answer:
The area that she painted = 896 mm^2
Step-by-step explanation:
Given:
The given figure is a pyramid with square base.
Here we need to find the surface area of the figure that need to be painted.
Surface area of a square pyramid = (S×S) + 2×S×L square.units
Where, S = side of the base L = slant height of the pyramid.
Now we have to plug in the given values.
Here S = 14, L =25
Plug in these values into the formula
= (14*14) + 2*14*25
= 196 + 700
= 896 mm^2
The area that she painted = 896 mm^2
Hope this will helpful.
Thank you.
Answer:
y=40
x=59
z=81
Step-by-step explanation:
therfore..40+59+81=180