In the arcuate ABC, ad = BD, AE = EC, the area of triangle ABC is equal to 120 square centimeter

In the arcuate ABC, ad = BD, AE = EC, the area of triangle ABC is equal to 120 square centimeter

Let f be the midpoint of BC, connecting DF and EF, because D, e and F are all the midpoint, so AC ‖ DF, ab ‖ EF, BC ‖ De
We can know that the area of trapezoid is 3 / 4 of the area of ABC,
Trapezoid area = 3 / 4 × 120 = 90 square centimeter

In RT △ ABC, if ∠ C = 90 ° AB = 12, point D is the midpoint of edge AB, and G is the center of gravity of △ ABC, then GD=______ ．

In ∵ RT △ ABC, ∵ C = 90 °, ab = 12, D is the middle point on the edge ab.. CD = 12ab = 6.. GD = 13CD = 2