Answer: 3
3,000,000,000
Step-by-step explanation:
Billions have 9 zeros
21 blocks, because if he uses 38 you subtract 17 and you get 21
Answer: Tthe tower is 129 feet tall.
Step-by-step explanation:
According to trigonometry in a right triangle:

Let x be the height of the tower.
Given , 
Since tower stands vertical to the ground, that means it is making a right triangle with the shadow.
![\tan 65^{\circ}=\dfrac{x}{60}\\\\\Rightarrow\ 2.1445=\dfrac{x}{60}\ \ \text{[Using calculator]}\\\\\Rightarrow x= 2.1445\times60=128.67\approx129\text{ feet}](https://tex.z-dn.net/?f=%5Ctan%2065%5E%7B%5Ccirc%7D%3D%5Cdfrac%7Bx%7D%7B60%7D%5C%5C%5C%5C%5CRightarrow%5C%202.1445%3D%5Cdfrac%7Bx%7D%7B60%7D%5C%20%5C%20%5Ctext%7B%5BUsing%20calculator%5D%7D%5C%5C%5C%5C%5CRightarrow%20x%3D%202.1445%5Ctimes60%3D128.67%5Capprox129%5Ctext%7B%20feet%7D)
Hence, the tower is 129 feet tall.
<h3>Answer:</h3>
a) l = 5 + 2w
b) P = 2(l +w) = 2(5 +2w +w)
c) w = 8 cm, l = 21 cm
<h3>Explanation:</h3>
a) Using w for width, twice the width is 2w, and 5 more than that is 5+2w. This is your expression for l:
... l = 5 + 2w
b) The perimeter is the sum of the lengths of all sides, so is the sum of twice the length and twice the width.
... P = 2(l +w) = 2(5 +2w + w) . . . . substituting for l using the expression of (a)
c) Substituting the given perimeter, we have ...
... 58 = 2(5 +3w) = 10 + 6w . . . . . collect terms, eliminate parentheses
... 48 = 6w . . . . . . . . . . . . . . . . . . subtract 10
... 8 = w . . . . . . . . divide by 6
... l = 5 + 2·8 = 21 . . . . . find length using the formula for it
Dimensions are in centimeters, so we can write the solution as ...
- width = 8 cm
- length = 21 cm