Congruent because you can map the triangles using a reflection across the y-axis which is a rigid motion
Since 15409-1=15408 and 15408+1=15409, we can write that as one. With 15409-2, we can write the same thing with 15407+2
False.
<span>a diamond is a quadrilateral and it isn't a square. A quadrilateral is a shape that has 4 equal sides</span>