Help W/ Use of the Pythagorean Theorem?

Question

a^2+b^2=c^2
I need to find 4^2+b^2=8^2

How do you work out pythagorean when the missing number is a^2 or b^2? I know how to work it out if the missing number is c^2, but not a or b. Please explain, or send me a website that explains.

Thanks,
"Lizzie D"

Answer 1

you have the right formula to solve it.

4^2+b^2=8^2

4^2=16 (you get this by multiplying 4 twice (4*4)
b^2=can't do because that's what your solving for
8^2=64 (get this by multipying it twice (8*8)

now the problem is:
16+b^2=64
1. subtract 16 from both sides (the sides are 1. before the = sign and after)

now it is:
b^2=48
2.find the square root of both sides
b^2 will turn to b and the 48 will turn to 6.9

answer:b=6.9
I hope I explained it well.

go here for help:
http://regentsprep.org/Regents/math/fpyth/Pythag.htm

Definition: It is believed that the statement of Pythagorean's Theorem was discovered on a Babylonian tablet circa 1900-1600 B.C. The Pythagorean Theorem relates to the three sides of a right triangle. It states that c2=a2+b2, C is the side that is opposite the right angle which is referred to as the hypoteneuse. a and b are the sides that are adjacent to the right angle. In essence, the theorem simply stated is: the sum of the areas of two small squares equals the area of the large one.
Also Known As: a squared + b squared = c squared. Or c2=a2+b2
http://math.about.com/cs/pythagorean/g/pythagdef.htm

Answer 2

The lacking parent must be the perpendicular line. Pythagoras Theorem: The sq. on the hypotenuse is comparable to the sum of the squares of the different 2 aspects. hence: 17² = p² + 8² p² = 17² - 8² p = ?225 = 15. = answer.. d.

Answer 3

Solve for b²: b² = c² - a².
In your case b² = 8² - 4² = 64 - 16 = 48.
So b = √48 = 4√3.

Answer 4

C^2 is ALWAYS on the right side of the equation (c is the hypotenuse side of the right triangle). Since b= square root of 48, and you are trying to find a, your equation would be: a^2+sq.rt.48=c^2. If you are solving for c your equation would be: 4^2+sq.rt.48=c^2.
I hope this helpes!! :)

Answer 5

what you need to do is to to take either the A^2 or the B^2 (the other value you know to the other side of the equation (=)). to do this you will need to subtract it from both sides. example:

a^2 = c^2-b^2 or b^2=c^2-a^2.

then all you have to do it take the square-root of both sides and you have your answer. This will work on any algebraic equation that you have to solve.

Answer 6

fill the equation in, like this:

2^2+b^2=5^2

square everything,

4+b^2=25

subtract,

b^2=21

and square root everything

b=√21

Answer 7

b=(the square root of)8^2-4^2

Answer 8

Just do it backwards... if a2 + b2 = c2, then c2 - a2 = b2, etc...