Explanation:
A square has all the sides equal
If AD which is a side is 11, all other sides are 1
BC is 11
AC is a diagonal that divides the square and forms a triangle
AD =11
CD =11
Use Pythagoras theorem to find AC which is hypotenuse
AC² = AD² + CD²
= 121 + 121
=242
If AC² = 242, then AC is square root of 242
AC = 15.56 (approximate if required) 15.6 to 1d.p if required
BD = AC = 15.56
EC is half of BD and AC = 15.56/2
EC = 7.78 (check the decimal place required) 7.8 to 1d.p if required
Angle DAB is 90
Angle AEB is 90
Angle CBD is 45
Angle BAC is 45
(Add the units)
Quadrilateral C with 4 congruent sides is a square, all opposite sides are congruent
Quad L is a parallelogram, consecutive angles are supplementary and opposite angles are congruent