Question

Say that a and b are the lengths of the legs of a right triangle and c is the length of the hypotenuse. Find b if a = 21 and c = 29.
A) b =40
B) B = 20
C) B= 10
D) B = 400

Answer 1

Pythagorean *whistles*
You're welcome

Answer 2

\( \color{Black}{\Rightarrow 21^2 + x^2 = 29^2 }\)

Answer 3

21²= 441

Answer 4

Correct?

Answer 5

\( \color{Black}{\Rightarrow x^2 = 29^2 - 21^2 }\)

\( \color{Black}{\Rightarrow x^2 = 841 - 441 }\)

\( \color{Black}{\Rightarrow x^2 = 400 }\)

\( \color{Black}{\Rightarrow x = \sqrt{400} = ...? }\)

Answer 6

So it would be 25²+400=29²

Answer 7

29²=841

Answer 8

How did you get that 25 :/

Answer 9

typo.. I meant 21²

Answer 10

Exactly

Answer 11

\( \color{Black}{\Rightarrow x^2 = 841 - 441 = 400 }\)

Answer 12

Wow, thanks, that helped alot.

Answer 13

\( \color{Black}{\Rightarrow x = \sqrt{400} }\)

Answer 14

its b 20cm

Answer 15

@harshendu_pandey maybe you would like to explain your answer :)

Answer 16

don't answer for them... it's open STUDy not openAnswers... :P

Answer 17

@Ruhhr

Answer 18

from pythagoras theorum c2=a2+b2
b2=c2-a2
b2=(29)2-(21)2
b2=841-441
b2=400
b=20

Answer 19

Good, but I had already explained the same :P

Answer 20

Wait I don't understand how it's 20 when I got 400

Answer 21

What is square root of 400?

Answer 22

b2 is 400... you still need to take the quare root to get b...

Answer 23

\( \color{Black}{\Rightarrow x \times x = 400 }\)

There's one number that when is multiplied to itself, gets you 400. That number is 20 :D

Answer 24

There are actually two solutions. -20 or 20, but a side of a triangle can't be in negative :)

Answer 25

So there is only one solution to this answer.

Answer 26

Oh, alright, got it!

Answer 27

Hah! nice!