Question #3063d

2 Answers
Nov 11, 2017

Check the method below.

Explanation:

Pythagorean's theorem states that in a right triangle, a^2+b^2=c^2a2+b2=c2, where cc is your hypotenuse, or the angle opposite of the right angle, and aa and bb are either of your legs, or sides attached to the right angle.

For your first problem, you have both sides. Plug them into the theorem.

3^2+3^2=c^232+32=c2
9+9=c^29+9=c2
18=c^218=c2
sqrt(c^2)=sqrt(18)c2=18
c=sqrt(9)sqrt(2)c=92
c=3sqrt(2)c=32

For your second problem, use the same theorem. However, note we're missing a leg and we have the hypotenuse already. Plug in accordingly.

40^2+b^2=65^2402+b2=652
1600+b^2=42251600+b2=4225
b^2=2625b2=2625
b~~51.2b51.2

Nov 11, 2017

a^2+b^2=c^2a2+b2=c2

Explanation:

Each of these problems uses the Pythagorean Theorem/Pythagoras' Theorem.

This theorem states that for a right angled triangle with hypoteneuse cc and sides aa and bb, a^2+b^2=c^2.a2+b2=c2. The hypoteneuse is the side opposite the right angle, and is always the longest side on a right angled triangle.
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Example 1

For the first example, a=3a=3 and b=3b=3.

a^2+b^2=c^2a2+b2=c2
3^2+3^2=c^232+32=c2
c^2=18c2=18
At this point you can either take out your calculator to do sqrt1818, or simplify the surd to get
c=3sqrt2c=32

Example 2

For this problem, we need to re-arrange Pythagoras' theorem to make a^2a2 the subject (because its neater to have squares than square roots and squares).

a^2+b^2=c^2a2+b2=c2
a^2=c^2-b^2a2=c2b2
Now, we sub in our values
a^2=65^2-40^2a2=652402
a^2=4225-1600a2=42251600
a^2=2625a2=2625
Now using your calculator
a=sqrt2625=5sqrt105~~51.2fta=2625=510551.2ft