Answer:
y = -8
Step-by-step explanation:
y = -10 - x
y = -10 - (-2)
y = -10 + 2
y = -8
You can use the ASA postulate which means angle side angle. if 2 angles and the including side are congruent to the corresponding parts of another triangle then the triangles are congruent. hope that helps :)
To find the midpoint of a line use the midpoint formula which is M = (x1+x2/2 , y1 +y2/2) After plugging in the coordinates for your variables you should get (-1+5/2, -1+2/2) This simplifies to (2, 1/2) which is the coordinates for the middle point of the base XY.
