If you start on page 20 and end on Page 50, you will have read 31 pages. I just counted from 20 to 50, including the number 20 in it.
OR: You already know there are 50-20=30 pages. But that's without counting the 20 in it. So when you add the extra 20: 30 + 1 = 31
Translated version:
Если вы начнете со страницы 20 и закончите со страницы 50, вы прочтете 31 страницу. Я только что насчитал от 20 до 50, включая число 20 в нем.
ИЛИ: Вы уже знаете, что 50-20 = 30 страниц. Но это без учета 20 в нем. Поэтому, когда вы добавляете дополнительные 20: 30 + 1 = 31
Я использовал Google Translate, поэтому результаты могут быть неточными.
Measure of Angle 2 = 100 degrees
measure of Angle 6 = 100 degrees
Since angle 2 and angle 6 are both 100 degrees, this makes them congruent angles. They are also corresponding angles as well.
The fact we have corresponding angles that are congruent leads to AB being parallel to CD. This is using the Converse of Corresponding Angles Theorem.
B
given f(x) in factored form, equate to zero for x-intercepts
(x - 8)(x - 4) = 0, hence
x = 4, x = 8 ← x- intercepts
The vertex lies on the axis of symmetry which is situated at the midpoint of the x- intercepts
x- coordinate of vertex = 
= 6
f(6) = (6 - 8 )(6 - 4 ) = -2 × 2 = - 4 ← y-coordinate
vertex = (6, - 4 ) → B
The answer is C; 35.5 units^2
