Download Pythagorean Theorem Pt. 2

Bell Ringer
Pythagorean
Theorem 2.0
Mr. Haupt
CC.2.1.8.A.2; CC.2.1.8.A.3
Reverse, Reverse
• You have practice using Pythagorean Theorem to find a
missing side of a triangle that we know is a right triangle.
• Now we are going to use it to decide if a triangle is right or not
when you are given all three sides.
• It is even easier than what we did yesterday.
• All you have to do is plug in the values, and see if a2 + b2 really
is equal to c2.
Examples
45-45-90 and 30-60-90
• When the two legs are the same, the hypotenuse is the length
of the leg times the square root of 2. So what are the lengths
when both legs are 5?
• If the angles measure 30, 60, and 90, then your short leg will
be x, the longer leg will be x times the square root of 3, and
the hypotenuse will be 2x.
Common Triples
• There are certain ratios where the sides of a right triangle are
nice and neat and easy to remember. There are a lot of them,
but these are the most common.
• Multiples of these ratios also count. So for 3-4-5, we can also
use 15-20-25 since if you reduce the numbers you still have 34-5.
• 3-4-5
• 5-12-13
• 8-15-17