Properties of equality have nothing to do with it. The associative and commutative properties of multiplication are used (along with the distributive property and the fact of arithmetic: 9 = 10 - 1).
All of these problems make use of the strategy, "look at what you have before you start work."
1. = (4·5)·(-3) = 20·(-3) = -60 . . . . if you know factors of 60, you can do this any way you like. It is convenient to ignore the sign until the final result.
2. = (2.25·4)·23 = 9·23 = 23·10 -23 = 230 -23 = 207 . . . . multiplication by 4 can clear the fraction in 2 1/4, so we choose to do that first. Multiplication by 9 can be done with a subtraction that is often easier than using ×9 facts.
4. = (2·5)·12·(-1) = 10·12·(-1) = (-1)·120 = -120 . . . . multiplying by 10 is about the easiest, so it is convenient to identify the factors of 10 and use them first. Again, it is convenient to ignore the sign until the end.
5. = 0 . . . . when a factor is zero, the product is zero
The height of a building is 58.08 meters if the angle is 71 degree and the distance between A and B is 20 meters.
<h3>What is trigonometry?</h3>
Trigonometry is a branch of mathematics that deals with the relationship between sides and angles of a right-angle triangle.
We have:
Angle = 71 degree
Distance between A and B = 20 meters
Let's suppose the height of the building is x meters.
From the right angle triangle applying the tan ratio:
tan71 = x/20
x = 58.08 meter
Thus, the height of a building is 58.08 meters if the angle is 71 degree and the distance between A and B is 20 meters.
Learn more about trigonometry here:
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Answer:
Step-by-step explanation:
8 times 6 = 48 (base times high = a rectangle). (A triangle takes half the space)
F. (6*8)/2 =24 square units
B. (2 * 3/2) / 2 = 3/2 = 1.5 square units
G. (4*3)/2 = 6 square units
H. (8/3 *2)/2 = 8/3 = 2.67 square units
Converting everything to decimals:
0.25 inch, 0.5 inch, 0.4 inch
Ordering:
0.25, 0.4, 0.5
Converting the appropriate numbers back to fractions:
1/4,10/25,0.5.
