You can focus on the two sub-triangles ABC and ACD
We know that they are both right triangles, because we're given that AC and BD are perpendicular.
The sides AB and AD are the hypothenuses of these triangles, so we know their length through the pythagorean theorem:
But since we're given 
, the expressions for AD and AB are actually the same expression. This proves that AD=AB, and thus that the triangle is isosceles.
Answer:
( 1 , 6 )
Step-by-step explanation:
sory if it is wrong
Answer:
The third one
Step-by-step explanation:
Slope is rise/run
This graphs shows the line going up by 2 and to the right 3
I think it is angle number 9
Answer:
The square root of 16 is rational.
Step-by-step explanation:
