We can solve for the value of x using pythagorean theorem

where c is the hypotenuse ( in this case is 15) and a, b are the other legs of the triangle ( in this case is 8 and x).
Let's substitute the given values to the formula

Now please follow this solution to solve for x in:
Answer:
12 pencils
Step-by-step explanation:
5 + 1 = 50% of the original amount
5 + 1 = 6
50% = 6
6 x 2 = 12 = 100%
Katie had 12 pencils
Answer:
YZ = 18
Step-by-step explanation:
XY = YZ because the line indicates they are the same length
XY = 18 so YZ = 18
To get the midsegment, namely HN, well, we need H and N
hmm so.... notice the picture you have there, is just an "isosceles trapezoid", namely, it has two equal sides, the left and right one, namely JL and KM
the midpoint of JL is H and the midpoint of KM is N
thus


![\bf \begin{array}{lllll} &x_1&y_1&x_2&y_2\\ % (a,b) K&({{ 4q}}\quad ,&{{ 4n}})\quad % (c,d) M&({{ 4p}}\quad ,&{{ 0}}) \end{array}\qquad % coordinates of midpoint \left(\cfrac{4p+4q}{2}\quad ,\quad \cfrac{0+4n}{2} \right) \\\\\\ \left( \cfrac{2(2p+2q)}{2},\cfrac{4n}{2} \right)\implies \boxed{[(2p+2q), 2n]\impliedby N}\\\\ -----------------------------\\\\](https://tex.z-dn.net/?f=%5Cbf%20%5Cbegin%7Barray%7D%7Blllll%7D%0A%26x_1%26y_1%26x_2%26y_2%5C%5C%0A%25%20%20%28a%2Cb%29%0AK%26%28%7B%7B%204q%7D%7D%5Cquad%20%2C%26%7B%7B%204n%7D%7D%29%5Cquad%20%0A%25%20%20%28c%2Cd%29%0AM%26%28%7B%7B%204p%7D%7D%5Cquad%20%2C%26%7B%7B%200%7D%7D%29%0A%5Cend%7Barray%7D%5Cqquad%0A%25%20%20%20coordinates%20of%20midpoint%20%0A%5Cleft%28%5Ccfrac%7B4p%2B4q%7D%7B2%7D%5Cquad%20%2C%5Cquad%20%5Ccfrac%7B0%2B4n%7D%7B2%7D%20%5Cright%29%0A%5C%5C%5C%5C%5C%5C%0A%5Cleft%28%20%5Ccfrac%7B2%282p%2B2q%29%7D%7B2%7D%2C%5Ccfrac%7B4n%7D%7B2%7D%20%5Cright%29%5Cimplies%20%5Cboxed%7B%5B%282p%2B2q%29%2C%202n%5D%5Cimpliedby%20N%7D%5C%5C%5C%5C%0A-----------------------------%5C%5C%5C%5C)