given the quadrilateral ABCD with two diagonals perpendicular and AB=8cm, BC=7cm, AD=4cm. Evaluate CD

Given the quadrilateral ABCD with two diagonals perpendicular and AB = 8cm, BC = 7cm, AD = 4cm. Evaluate CD.
Answer: CD = cm.

1.Given the quadrilateral ABCD with two diagonals perpendicular and AB = 8cm, BC = 7cm, AD = 4cm. Evaluate CD.

2.Given three consecutive even natural numbers, which have the product of last two numbers is 80 greater than the product of first two numbers.
Find the largest number.
Answer: The largest number is

Given a right prism ABC.A'B'C' that AB = 9 cm; BC = 15 cm; AC = 12 cm.

There are .... lines are perpendicular to the line AB.

Given a right prism ABC.A'B'C' that AB = 9 cm; BC = 15 cm; AC = 12 cm.

There are .... lines are perpendicular to the line AB.

Given a right prism ABC.A'B'C' that AB = 9 cm; BC = 15 cm; AC = 12 cm.

There are .... lines are perpendicular to the line AB.

3)Perpendicular lines An angle that has a measure of 90° is a right angle.If two lines intersect at right angles,the lines are perpendicular. d1 and d2 are perpendicular,denote​​d by d1_d2 . A right angle symbol in an angle of intersection indicates that the lines are perpendicular.( mấy bạn giúp mình nha minhf cảm ơn)))

3)Perpendicular lines An angle that has a measure of 90° is a right angle.If two lines intersect at right angles,the lines are perpendicular. d1 and d2 are perpendicular,denote​​d by d1_d2 . A right angle symbol in an angle of intersection indicates that the lines are perpendicular.( mấy bạn giúp mình nha minhf cảm ơn)))

give isosceles trapezoid abcd ( ab // cd,ab<cd) from a draw ah perpendicular ab , ah intersects bd at h . from b draw bk perpendicular ab , bk intersects ac at k a) what figure is quadrilateral ahkb?why? b) Given that E,F are the midpoints of AB, DC; I and G are respectively the intersection points of AC with BD , CH with DK . Prove that four points E,I,G,F are collincar