Question

Please help me I don’t understand what a special triangle is my teacher doesn’t teach us anything

Answer 1

AB :

cos45=AB/AC

cos45=AB/4

AB = 4*cos(45)=2√2≈2.8

Explanation:

Answer 2

The missing sides are equal to 2.828

Explanation:

This is a 45-45-90 right triangle meaning that the two missing sides have the same length. The ratio of the hypotenuse to one of the sides is √2:1 so 4/√2=s/1

4/√2≈2.828

2.828=s/1

2.828=s

s=side

You can also solve this using trigonometry.

sin=opposite/hypotenuse

cos=adjacent/hypotenuse

Since both opposite and adjacent sides are the same, you can use either sin or cos.

sin45=s/4

0.707=s/4

4 x 0.707=s

2.828=s