Amira is writing a coordinate proof to show that the area of a triangle created by joining the midpoints of an isosceles triangles is one-fourth the area of the isosceles triangle. she starts by assigning coordinates as given. triangle d e f in the coordinate plane so that vertex d is at the origin and is labeled 0 comma 0, vertex e is in the first quadrant and is labeled 2 a comma 2 b, and vertex f is on the positive side of the x-axis and is labeled 4a comma 0. point q is between points d and e. point r is between points e and f. point p is between points d and f and is labeled 2 a comma 0. enter your answers, in simplest form, in the boxes to complete the coordinate proof. point q is the midpoint of de¯¯¯¯¯ , so the coordinates of point q are (a, b) . point r is the midpoint of fe¯¯¯¯¯ , so the coordinates of point r are ( , b). in △def , the length of the base, df¯¯¯¯¯ , is , and the height is 2b, so its area is . in △qrp , the length of the base, qr¯¯¯¯¯ , is , and the height is b, so its area is ab . comparing the expressions for the areas proves that the area of the triangle created by joining the midpoints of an isosceles triangle is one-fourth the area of the