Which of the following is NOT a property of an isosceles trapezoid? Lower base angles are congruent
One pair of opposite sides are parallel
Diagonals are perpendicular
One pair of opposite sides are congruent

Ascientist has 50 grams of a radioactive element. the amount of radioactive element remaining after t days can be determined using the equation (1) after two days the scientist receives a second shipment of 50 grams of the same element. the equation used to represent the amount of shipment 2 remaining after t days is 10) - 50 which of the following is an equivalent form of the expression for the amount remaining in shipment 2? what’s the answer?