1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Nimfa-mama [501]
3 years ago
15

Find the perimeter of right triangle WXY if the radius of the circle is 4 units and WY = 20 units.

Mathematics
1 answer:
Novosadov [1.4K]3 years ago
5 0
Remark
This problem is one of those little gems you come across every so often. It has a couple of things worth knowing even if it is a little late.

Step One
Find a + b [which are the two legs of the triangle.]
r = the inradius
r = 4 in this question.
r = (a + b - c)/2 where c is the hypotenuse. This is easily proved. If you can't, google inradius and perimeter.
4 = (a+b - 20)/2  Multiply by 2
4*2 = a+b - 20
8 = a+b - 20 Add 20 to both sides.
8 + 20 = a + b
28 = a + b

Step two 
Set up the Pythagorean Theorem
a^2 + b^2 = c^2
a^2 + b^2 = 20^2
a^2 + b^2 = 400

Step three
Expand (a + b)^2 to find ab
(a + b)^2 = a^2 + 2ab + b^2
(28)^2 = a^2 + b^2 + 2ab
Remember that a^2 + b^2 = 400
28^2 = 400 + 2ab
784 = 400 + 2ab     Subtract 400 from both sides.
784 - 400 = 2ab   
384 = 2ab              divide by 2
384/2  = ab
ab = 192

Step 4 
Find a and b
ab = 192
a + b = 28
b = 28 - a

ab = 192                    Substitute 28 - a for b
a(28 - a) = 192
-a^2 + 28a = 192
-a^2 + 28a - 192 = 0

You have to use the quadratic formula.
a = -1
b = 28
c = - 192

\text{x = }\dfrac{ -b \pm \sqrt{b^{2} - 4ac } }{2a}

When you solve this you get 2 roots.
a = 12 and b = 16 These are the two sides of the triangle or
a = 16 and b = 12
Check
a^2 + b^2 =? 20^2
12^2 + 16^2 = ?400
144 + 256 =? 400
400 = 400

The problem does check
Neat little problem Thanks for posting. 

I would solve 2*r = (a + b - c) for you but I can't get the many diagram programs to work properly for labeling these diagrams. 

There are great discussions on how to make the incircle radius an integer value by choosing the triangle sides with an integer value.
You might be interested in
A line passes through the points (0, –3) and (2, –4) . What is the slope of the line?
Fudgin [204]
<span>(0, –3) (2, –4)
slope = difference in y divided by </span><span>difference in x
</span>
<span>slope = (-3 --4) / (0 -2) =
1 / -2

</span>
3 0
3 years ago
Read 2 more answers
Rachna purchases a plant that is 6 inches tall. Every week the plant grows an additional 0.6 inches. Rachna draws a graph of the
aleksklad [387]

Answer:

0.6

Step-by-step explanation:

Slope is the change in y divided by change in x.

x is weeks

y is height

We know plant grows 0.6 inches every week. This means per 1 week [change in x], the plant grows 0.6 inches [change in y]

Slope = 0.6/1 = 0.6

0.6 is the slope of the function

5 0
3 years ago
A map has a scale of 1 in: 10 mi. On the map, the distance between two cities is 5 inches. What is the actual distance between t
Schach [20]
50 miles since 1 inch equals 10 miles and there's 5 inches that means 5x10=50
4 0
3 years ago
What is 54 in the ratio 5:11:2
qwelly [4]
5/22 I’m pretty that’s the answer
6 0
2 years ago
99,000 equals how much tens
In-s [12.5K]
9900  because you divide 99000 by 10
3 0
3 years ago
Read 2 more answers
Other questions:
  • If you have three cups of pineapple juice how many total cups of punch can you make
    6·1 answer
  • Wendy had 1/2 of her birthday cake left over, so she decided to take it to work.
    7·2 answers
  • Solve the following equation for y.
    13·2 answers
  • Juan's cell phone company charges $35 a month for phone service plus $0.50 for each text message. How many text messages does ju
    15·1 answer
  • For what values of x is each function increasing? For what values of x is it decreasing? a. f(x) = x2 - 4x​
    8·1 answer
  • Please help it is due in less than an hour and it is my last day to do it before the end of the quarter,
    13·1 answer
  • The population of a county is growing at a rate of 9% per year, compounded continuously. How many years will it take for the pop
    10·1 answer
  • Consider the cartesian equation of a circle, y=-2+- sqrt 36-(x-1)^2 , verses the parametric equations of the same circle: x=1+6
    12·1 answer
  • The segment.
    12·1 answer
  • A ball is launched into the sky at 54. 4 ft./s from a 268.8 m tall building. The equation for the ball’s height, h, at time t se
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!