The shorter leg of a right triangle is 21 feet less than the other leg. Find the length of the two legs if the hypotenuse is 39 feet.

Respuesta :

Answer:

leg 1= 36  feet

leg2 = 15  feet

Step-by-step explanation:

Hi, we have to apply the Pythagorean Theorem:  

c^2 = a^2 + b^2  

Where c is the hypotenuse of the triangle (in this case the distance between Doreen’s house and the tower) and a and b are the other legs.  

leg1 = x

leg2 = x-21 (21 feet less than the other leg)

Replacing with the values given:  

39^2 = x^2 + (x-21)^2  

1,521 = x^2 + x^2 -42x +441

0 = 2x^2 -42x +441-1,521

0= 2x^2 -42x -1,080

For: ax2+ bx + c  

x =[ -b ± √b²-4ac] /2a  (quadratic formula)

Replacing with the values given:  

x=-(-42)± √(-42)²-4(2)-1080] /2(2)  

x= 42± √10,404] /4

x = 42± 102 /4

Positive:

x = 42+102 /4 = 36

leg 1= 36

leg2 = 36-21 =15

Feel free to ask for more if needed or if you did not understand something.  

The length of shorter leg is 15 feet and other leg is 36 feet.

Pythagoras theorem:

Let us consider that, length of shorter leg is x feet.

So that, length of other leg is [tex](x+21)[/tex] feet.

It is given that, the hypotenuse is 39 feet.

Apply Pythagoras theorem,

                 [tex]x^{2} +(x+21)^{2} =(39)^{2}\\ \\x^{2} +x^{2} +441+42x=1521\\\\2x^{2} +42x-1080=0\\\\x=15 ,-36[/tex]

Since, side can not be negative.

So that, we have to consider x=15 feet.

Length of other leg[tex]=x+21=15+21=36feet[/tex]

Learn more about the Pythagoras theorem here:

https://brainly.com/question/343682