Kayla had 3/4 of her book left to read on Sunday night.she read 1/5 of the book Monday afternoon and 1/4 of the book Monday even
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Answer:
182 ft
Step-by-step explanation:
When you are not given a diagram, always draw one for yourself (see diagram).
When you have a right triangle (triangle with 90° angle), you can use the trigonometry ratios, You can remember them using SohCahToa. It is read like this:
<u>s</u>inθ = <u>o</u>pposite/<u>h</u>ypotenuse Soh
<u>c</u>osθ = <u>a</u>djacent/<u>h</u>ypotenuse Cah
<u>t</u>anθ = <u>o</u>pposite/<u>a</u>djacent Toa
"θ" means the angle of reference (the angle you are talking about).
We are looking for the length of BC, which is the <u>hypotenuse</u>. I labelled it "d" (lowercase D) because it is opposite to ∠D.
We know ∠C = 77°. This will be our angle of reference (replace θ).
The side we know is DC, also known as "b" (lowercase B) because it's opposite to ∠B. "b" is the <u>adjacent</u> side when θ = C because "b" is touching ∠C.
Take the general trig. formula that has <u>hypotenuse</u> and <u>adjacent</u>: (cosine ratio)
cosθ = adjacent/hypotenuse
Substitute the variables specific for this problem.
cosC = b/d
Substitute the values you know.
cos77° = (41 ft) / d
Isolate "d" to the left side
dcos77° = Multiply both sides by "d"
dcos77° = 41 ft
dcos77° / cos77° = 41 ft / cos77° Divide both sides by cos77°
d = 41 ft / cos77° Input into calculator
d = 182.261874....... ft Unrounded answer
d ≈ 182 ft Rounded to nearest foot (whole number)
Remember d = BC. It's often easier to use one letter for calculations.
Therefore the length of BC is about 182 feet.
Answer:
15 hours
Step-by-step explanation:
Given:
Fernell's speed mph
Dabney's speed mph
Denote:
- distance covered by Fernell
- distance covered by Dabney
- Fernell's time
- Dabney's time
1. If Fernell drove for 3 hours longer than Dabney, then his time is 3 hours more than Dabney's time and
2. If Fernell covered 18 miles less than Dabney, then
Use formula
Subtract from the first equation the second equation and equate it to 18: