Given a trapezoid ABCD with base AB=4cm , CD=6cm ,  and góc C + góc D = 90 độ . Let M, N be respectively the midpoints of the segments AB and CD . Evaluate MN.
Answer: MN= ? cm

Let ABC be a triangle with AB = 3cm, AC = 7cm. The internal bisector of the angle BAC intersects BC at D. The line passing through D and parallel to AC cuts AB at E. Find the measure of DE. Answer: DE = ..........cm.

Let ABCD be a trapezoid with bases AB, CD and O be the intersection of AC and BD. If the areas of triangle OAB, triangle OCD are 16cm², 40cm²respectively and M is the midpoint of BD, then the area of the triangle AMD is  .........cm².

Let ABCD be a trapezoid with bases AB, CD and O be the intersection of AC and BD. If the areas of triangle OAB, triangle OCD are 16cm², 40cm²respectively and M is the midpoint of BD, then the area of the triangle AMD is .........cm².

Let ABC be a triangle with AB = 3cm, AC = 7cm. The internal bisector of the angle BAC intersects BC at D. The line passing through D and parallel to AC cuts AB at E. Find the measure of DE.
Answer: DE = ..........cm.

Write your answer by fraction in simplest form

trapezoid ABCD with AB // CD , AB < CD , AD = BC = AB , the angle BDC = 30 degrees . calculate the angles A, B ,C ? help me 

Let ABCD be a trapezoid with bases AB, CD and O be the intersection of AC and BD. If the areas of triangle OAB, triangle OCD are 16cm², 40cm²respectively and M is the midpoint of BD, then the area of the triangle AMD is  .........cm².

Bạn nào giúp mk vs!!!

Said quadrangle ABCD for the measurement of the angle A; B; C; D proportional voi5; 8; 13va 10.A / Count measure the angles of a quadrilateral ABCDb / Extend sides AB and DC intersect at E, which lasted two sides AD and BC in F. Two-rays catnhau sense of angles AED and corner cutting AFB O. Separate each corner giaccua AFB cutting edge CD and AB at M and N. Prove cuadoan MN O is the midpoint.