#3 Special Right Triangles 45 45 90 4.notebook
January 27, 2015
12/16 ­ Special Right Triangles
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o
o
Obj.: To use properties of 45 ‐ 45 ‐ 90 triangles
Leg
Activity
Draw a square and make each side equal...
1. 2
x
2. 3
3. 4
Then, find the length
4. 5
of the diagonal (HINT:
5. 6
use Pythagorean Thm).
6. 7
7. 8
o
o
o
Can we come up with a pattern for all 45 - 45 - 90 triangles?
45
Hypotenuse
Leg
2
o
Hypotenuse
3
Leg
4
45
o
5
Leg
6
7
8
Leg =
Hypotenuse =
The ratio of the sides is always 1:1:____.
Dec 9­2:26 PM
Dec 9­2:37 PM
Examples:
Closure Question
Find x and y.
x in
2.
4 in
x in
1.
Make 1 notecard (yes on an actual notecard, not paper)
45o
Special Right Triangles
45-45-90
in
45O 45o
y in
y in
X√2
30 O
x
60 O
45O X
x√3
X
BACK
FRONT
3.
Special Right Triangles
2x 30-60-90
45o
6 cm
x cm
y cm
Dec 9­2:43 PM
Homework
G.SRT.5WS #2 problems #1 c,f,h,j,n,p,q,s
#2 a,d,f,h,i and #3 c,d
Dec 9­2:52 PM