Let x=ab=ac, and y=bc, and z=ad.
Since the perimeter of the triangle abc is 36, you have:
Perimeter of abc = 36
ab + ac + bc = 36
x + x + y = 36
(eq. 1) 2x + y = 36
The triangle is isosceles (it has two sides with equal length: ab and ac). The line perpendicular to the third side (bc) from the opposite vertex (a), divides that third side into two equal halves: the point d is the middle point of bc. This is a property of isosceles triangles, which is easily shown by similarity.
Hence, we have that bd = dc = bc/2 = y/2 (remember we called bc = y).
The perimeter of the triangle abd is 30:
Permiter of abd = 30
ab + bd + ad = 30
x + y/2 + z =30
(eq. 2) 2x + y + 2z = 60
So, we have two equations on x, y and z:
(eq.1) 2x + y = 36
(eq.2) 2x + y + 2z = 60
Substitute 2x + y by 36 from (eq.1) in (eq.2):
(eq.2') 36 + 2z = 60
And solve for z:
36 + 2z = 60 => 2z = 60 - 36 => 2z = 24 => z = 12
The measure of ad is 12.
If you prefer a less algebraic reasoning:
- The perimeter of abd is half the perimeter of abc plus the length of ad (since you have "cut" the triangle abc in two halves to obtain the triangle abd).
- Then, ad is the difference between the perimeter of abd and half the perimeter of abc:
ad = 30 - (36/2) = 30 - 18 = 12
Answer:
The answer is
Step-by-step explanation:
This is from khan academy. so You need to watch a video on khan academy to get help.
If Bobby claims Peter started with 21 cards, then we'll work this into our equation.
21 - 3 (that he lost) = 18
18 / 2 (the half he gave) = 9
So this means that he did have 21 cards to begin with. Please reply to this with a list of the answers that can/could be checked!
2 oranges cost $2 . $9 - $2 = $7
then 12 apply of Lisa and 6 apples of Jeremy
= 18 ÷ 7 = 2.57. $2.57 for 6 apples
2.57 ÷ 6 = 0.43 each apple
Answer:
B) identity property of addition.
Step-by-step explanation:
Given:
The statement given is:
Here, we observe that 10 is added to a giving the number 10 itself as the answer. So, we know of a property which says that when 0 is added to a number, the result is the number itself. This property is called identity property of addition.
So, the value of 
must be 0 because on adding to 10, we are getting the number 10 only. So, the above statement is an example of identity property of addition.
