How do you use the Pythagorean Theorem to find the missing side of the right triangle with the given measures: b = 5, c = 8?

3 Answers
May 14, 2018

Side A is #sqrt(39)# or 6.244997998.

Explanation:

Right, let write down the Pythagorean Theorem equation or standard form of it. before we plug in the numbers.

#a^2 + b^2 = c^2#

Right, so that is the equation of Pythagorean Theorem. So let plug in the numbers of b and c.

#a^2 + 5^2 = 8^2#

So we have our values of b and c. Now, how do we find the missing number?

Well, let simplify thing further by squaring the numbers we have already.

#a^2# + 25 = 64

We will now subtract 25 from both side which gives us:

#a^2# = 39

Now we can square root the answer.

#sqrt(a^2) # = #sqrt(39)#

Now, we are left with this:
a = #sqrt(39)#

Now, I am unsure if you want decimals or not. But if you were to square 39 into your calculator by pressing a few keys, it would give you this unless you switched mode.

On my calculator model of TI-36XPro, I pressed "mode" and went to the bottom and switched from Hathprint to Classic which gives me decimals of square roots.

So the final answer is #sqrt(39)# or the decimal value of #sqrt(39)# is 6.244997998.

May 14, 2018

#a = sqrt39#

Explanation:

The Pythagorean Theorem is #a^2 + b^2 = c^2#

You can then substitute the numbers b and c to get:
#a^2+5^2=8^2#
#a^2+25=64#

You can then make #a^2# on its own by #-25#
#a^2=39#

Then square root both sides to get:
#a = sqrt39#

May 14, 2018

If you are finding the hypotenuse

#5^2+8^2=a^2#

#25+64=a^2#

#a=sqrt89#

a=9.433981132

If #c# is the hypotenuse then

#8^2-5^2=a^2#

#64-25=a^2#

#a=sqrt39#

a=6.244997998