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
The true statements about the triangles RST and DEF are: (a), (d) and (e)
<h3>How to determine the true statements?</h3>
The statement ΔRST ≅ ΔDEF means that the triangles RST and DEF are congruent.
This above implies that:
- The triangles can be mapped onto each other by rigid transformations such as reflection, translation and rotation
- The transformation does not include dilation
- Corresponding sides are congruent
The above means that the possible true statements are: (a), (d) and (e)
Read more about transformation at:
brainly.com/question/4289712
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Answer:
3??
Step-by-step explanation:
Im saying 3 because i need to know when it will end, If you divide it by 5 it will say 3 now you can delete this or something if im wrong, You really have not described how much she will have at the end of the week.
z=-3
Step-by-step explanation:
To find the area of the rectangle, do A=lw which is 4x13=52. to find the area of the triangle, first find the height. this is 13-6=7. now do A=bh/2 which is (5x7)/2=17.5. 17.5+52=69.5 which is your answer. DONT OPEN ANY LINKS ON HERE, ITS A VIRUS
