Cho tam giác abc vuông tại a, có d là trung điểm của cạnh bc biết ab=6cm;ac=8cm a/ tính độ dàme ad
b/ kẻ dm vuông góc ab, dn vuông góc ac. chứng minh tứ giác amdn là hình chứ nhật
c/ tam giác abc phải có thêm điều kiện gì để tứ giác amdn là hình vuông?

50-38=12

step-by-step explanation:

false

step-by-step explanation:

false.   two legs of the trapezoid would be congruent, but the other two would not.   were all the legs congruent, then we'd have a square; were the 2 shorter sides congruent and the 2 longer sides also congruent, we'd have a rectangle.

d) by the cross product property, ab^2 = bc multiplied by ad

step-by-step explanation:

we are given

in the given triangle abc

angle a is 90° and segment ad is perpendicular to segment bc

we can see that

triangle(abc) and triangle(abd) are similar because they have common side and same angle (90 degree)

so, triangles(abc) and abd are similar

since, they are similar

so, the ratio of their sides must be equal

we get

now, we can cross multiply

and we get

so, this could be step to prove it

answer: both chords and diameters have two endpoints on a circle. diameters must intersect the center of a circle.