If the diagonals of a quadrilateral are perpendicular, then it is a rhombus. False, diagonals don't have to be congruent or bisect each other. The diagonals of a rectangle bisect its angles. A kite with all consecutive angles congruent must be a square.
![-20 \leq 3x+1 \leq 10\\ \Rightarrow\ -21 \leq 3x \leq 9\\ \Rightarrow\ -7 \leq x \leq 3\\ Sol=[-7\ 3]\ if\ x\ is\ a\ real. ](https://tex.z-dn.net/?f=-20%20%5Cleq%203x%2B1%20%5Cleq%2010%5C%5C%0A%5CRightarrow%5C%20-21%20%5Cleq%203x%20%5Cleq%209%5C%5C%0A%5CRightarrow%5C%20-7%20%5Cleq%20x%20%5Cleq%203%5C%5C%0A%0ASol%3D%5B-7%5C%203%5D%5C%20if%5C%20x%5C%20is%5C%20a%5C%20real.%0A)