For addition and subtraction the answer should have the same number of decimal places as the least number of decimal places involved in the operation. For multiplication and division the number of significant value of the answer should be the same as the least number of significant values of the involved numbers.
a. 26 x 0.02584 = 0.67
b. 15.3: 1.1 = 14
c. 782.45 - 3.5328 = 778.92
d. 63.258 + 734.2 = 797.5
If you meant 3456789+(pi/2) or also known as 3456789 plus half of pi,
Then the answer is 3456790.571
Answer:
For trapezoids, we have some rules:
The angles always need to ad up to 360°
We also have that the base angles are suplementary, so they need to ad to 180°. (one smaller or equal than 90° and the other greater or equal than 90°)
Then, if the angles are one equal to 60° and the other 45°.
The other two angles are:
a1 = 180° - 60° = 120°
a2 = 180° - 45° = 135°
and now we have: 120° + 60° + 45° + 135° = 360°
for the other we have an angle of 60° and other of 120°.
This two angles can be one next to the other, so may be suplementary.
this mens that the other two angles may be any angles that add to 180° (again, one is less or equal than 90° and the other is greater or equal than 90°)
So we can have:
a1 = 110°
a2 = 70°
for example.
There are 
ways of building a subset of 
elements from 
, so the total number of subsets you can build is
Recalling the binomial theorem, the above sum is equal to
as required.
Start here: A = 18 ft^2 = L * W. Next, L = 2W.
Merging these 2 formulas lets us eliminate L:
18 ft^2 = (2W) * (W) = 2W^2.
So W^2 = 9 ft^2, and W=3 ft. Please use L = 2W (from above) to calculate L.
