The area of parallelogram abed and AFCD are both 30 square centimeters. AF is perpendicular to ED, Ao, OD and ad, which are 3 cm, 4 cm and 5 cm respectively. Calculate the area and perimeter of triangle OEF

The area of parallelogram abed and AFCD are both 30 square centimeters. AF is perpendicular to ED, Ao, OD and ad, which are 3 cm, 4 cm and 5 cm respectively. Calculate the area and perimeter of triangle OEF

The length of of of is: 30 △ 4-3 = 4.5 (CM), the length of OE is: 30 △ 3-4 = 6 (CM), and the area of △ OEF is: 4.5 × 6 × 12 = 13.5 (square cm); because ad: EF = OA: of, that is, 5: EF: = 3:4.5, & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; 3ef = 5 × 4.5, & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; EF = 7.5; therefore, the perimeter of the triangle OEF is 4.5 + 6 + 7.5 = 18 (CM); a: the area of the triangle OEF is 13.5 square cm, and the perimeter is 18 cm

As shown in the figure, in the triangle ABC, BF is perpendicular to AC, CG is perpendicular to AB, FG is perpendicular, De is perpendicular to FG

Because △ GBC is a right triangle and D is the midpoint on the hypotenuse, Gd = BD = DC can be obtained. Similarly, FD = BD = DC can be obtained, so △ GFD is an isosceles triangle and E is the midpoint of GF