Answer:
A) 18.3
Step-by-step explanation:
Since adding b and a gives 19.
c must be less than 19.
So, A) 18.3 is the correct answer
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:
10 hours
Step-by-step explanation:
let x be the total number of hours
Amazing design total charge = 45x+250
super structures total charge = 60x+100
both companies charge the same amount when both equation equals
45x+250=60x+100
60x-45x=250-100
15x=150
x=10
therefore at 10 hours both companies will charge the same amount
Answer:
20%=8
10%=?
by cross multiplications,
10×8=80
80÷20=4
Hence the answer is 4.
Answer:
distance across the pond: 13 yd
distance walked by Garret: 12 yd
Step-by-step explanation:
Data:
- distance across the pond: x yd
- distance walked by Sandy: 5 yd
- distance walked by Garret: x-1 yd
A right triangle is formed where the distance across the pond is the hypotenuse. From Pythagorean theorem:
x² = 5² + (x-1)²
x² = 25 + x² - 2x + 1
0 = 26 - 2x
x = 13
