First and foremost that is a quadrilateral, because it is a 4-sided figure. If it was a trapezoid it would have only 1 set of parallel lines. So NOT a trapezoid. It is a parallelogram because parallelograms have 2 pair of parallel lines. It is not a rhombus because a rhombus has 4 equal length sides. So it's not a square either. It is not a rectangle either because rectangles have 4 right angles and this one does not. So your choices are 1 and 3.
3x + 50 = 6x -10
add 10 to each side
3x +60 = 6x
subtract 3x from each side
60 = 3x
x = 60/3 = 20
x = 20
B is correct because you wouldn't get the same answer as the other proportions if you solved it
Its cross-multiplication. 20.25 times 1 divided by 3 3/4 = 5.4 -(answer)
Answer:
a = 
Step-by-step explanation:
Using Pythagoras' identity in the right triangle.
The square on the hypotenuse is equal to the sum of the squares on the other 2 sides, that is
a² + 9² = 12²
a² + 81 = 144 ( subtract 81 from both sides )
a² = 63 ( take square root of both sides )
a = 