Answer:
10.5 ft.
Step-by-step explanation:
1. Find the radius of the larger circle
4/7 = 3/r --> the ratio should be <em>constant</em>
cross-multiplication: <em>21 = 4r</em>
Divide: <em>r = 5.25 ft.</em>
2. Find the circumference
Equation: <em>C = 2πr</em>
C = <em>2π*5.25</em>
C = 10.5π ft.
Answer:
24 quarters and 49 nickels
Step-by-step explanation:
This situation has two unknowns - the total number of nickels and the total number of quarters. Because we have two unknowns, we will write a system of equations with two equations using the two unknowns.
- n+q=73 is an equation representing the total number of coins
- 0.05n+0.25q=8.45 is an equation representing the total value in money based on the number of coin. 0.05 and 0.25 come from the value of a nickel and quarter individually.
We write the first equation in terms of q by subtracting it across the equal sign to get n=73-q. We now substitute this for n in the second equation.
0.05(73-q)+0.25q=8.45
3.65-0.05q+0.25q=8.45
3.65+0.20q=8.45
After simplifying, we subtract 3.65 across and divide by the coefficient of q.
0.20q=4.8
q=24
We now know of the 73 coins that 24 are quarters. To find the number of nickels, we subtract 24 from 73 and get 49 nickels.
Answer:
4.4 m
Step-by-step explanation:
Draw the height of the triangle (perpendicular line from point A to line BC). Since ABC is an isosceles triangle, the height is a perpendicular bisector, so it splits the triangle into two congruent right triangles.
Use Pythagorean theorem to find the height.
c² = a² + b²
(8.5 m)² = (14.5/2 m)² + h²
h ≈ 4.4 m
5π/12 = (5 · 180°) : 12 = 75°
cos 75° = cos ( 45° + 30° )= cos 45° cos 30° - sin 45° sin 30° =
=√2/2 * √3/2 - √2/2 * 1/2 =
=(2.4495 - 1.4142): 4 = 0.258825
