Move the triangle, 12 units right and 4 units bottom. Then, rotate it by 180 degrees. Transformation would be done!
Hope this helps!
Since he’s already at -15, if he writes a check for 7 then he’s subtracting more from his account.
So, -15-7=-22
Check the picture below.
now, we know that the slanted legs are congruent, since it's an isosceles trapezoid, we also know that the bases are the parallel sides, so, the "altitude" or distance from those bases are the same length, for each of those triangles in the picture.
now, the bases are parallel, that means the altitude segment is perpendicular to the base, the longest side at the bottom, so, we end up with a right-triangle that has a Hypotenuse and a Leg, equal to the other triangle's.
thus, by the HL theorem for right triangles, both of those triangles are congruent, and if the triangles are congruent, all their sides are also, including the ones on the base.