Hey there! :)
In order to the find the missing side length of this triangle, we'll need to use the Pythagorean Theorem!
That equation is : a² + b² = c²
a = adjacent side
b = long side of rectangle
c = hypotenuse
We're already given the values of both a & c, so let's plug everything in!
a² + b² = c² → a = 10 , b = ? , c = 20
(10²) + b² = (20²)
Simplify.
100 + b² = 400
Subtract 100 from both sides.
b² = 400 - 100
Simplify.
b² = 300
Get the square root of b² & 300.

Simplify!
b = 17.3
So, the missing side length is the first answer choice : 17.3~Hope I helped!~
Answer:
Does the correct answer necessarily HAVE to be one of those three options? Because I'm looking at the steps and there seems to no mistakes at all. Forgive me if I'm mistaken though!
Step-by-step explanation:
Work shown above! Answer would be A!
Answer:
2/5
Step-by-step explanation:
Ok there are 4+3+1+2 pairs of socks in all... Aka 10 sock pairs in all.
There are 4 white pairs. So the probability she selects a white pair is 4/10.
4/10 can be reduced to 2/5.