Idon’t understand this i don’t need an explanation can someone just me

Everyone else will be a congruent to the first one triangle.

SAS stands for "side, angle, side" and means that we have two congruent triangles where we know two sides and the included angle are equal.

step-by-step explanation:

this can be solved first with pythagorean theorem, which tells us to square both legs of the triangle and sum it. this will be equal to the square of the hypotenuse.

the hypotenuse is the side "opposite" the 90 degree angle, which is x.

so we can write using pythagorean theorem,

simplifying:

to further simplify this radical, we need to use the property  

thus