Answer:
C. 3/11
Step-by-step explanation:
If you divide 3/11, it's decimal will be: .272727272727... It is a repeating decimal and a irrational number .
The others are rational numbers and can be written out:
3/25 = .12
3/16 = .1875
3/8 = .375
Answer:
C. a = 7
D. c = -3
Step-by-step explanation:
C. 7(2a + 3) + 21 = 100+ 40
14a + 21 + 21 = 140
14a = 140 - 21 - 21
14a = 98
a = 7
D. 6+ 14 - 12c = 56
20 - 12c = 56
-12c = 56 - 20
-12c = 36
c = - 3
Answer:
The measure of an arc is equal to the angle opposite it
Therefore the answer is C. 100°
Hope this helps!
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
