Answer:
B. 12
Step-by-step explanation:
✔️Find the value of x
The side lengths of two similar triangles are always proportional.
Given that ∆ABC ~ ∆LMN, therefore:
AB = 5
LM = 10
AC = x + 5
LN = 3x + 3
Plug in the values
Cross multiply
(distributive property)
Collect like terms
Divide both sides by 5
x = 7
✔️Find AC
AC = x + 5
Plug in the value of x
AC = 7 + 5
AC = 12
Answer:
cos(θ) = 3/5
Step-by-step explanation:
We can think of this situation as a triangle rectangle (you can see it in the image below).
Here, we have a triangle rectangle with an angle θ, such that the adjacent cathetus to θ is 3 units long, and the cathetus opposite to θ is 4 units long.
Here we want to find cos(θ).
You should remember:
cos(θ) = (adjacent cathetus)/(hypotenuse)
We already know that the adjacent cathetus is equal to 3.
And for the hypotenuse, we can use the Pythagorean's theorem, which says that the sum of the squares of the cathetus is equal to the square of the hypotenuse, this is:
3^2 + 4^2 = H^2
We can solve this for H, to get:
H = √( 3^2 + 4^2) = √(9 + 16) = √25 = 5
The hypotenuse is 5 units long.
Then we have:
cos(θ) = (adjacent cathetus)/(hypotenuse)
cos(θ) = 3/5
