1a) False. A square is never a trapezoid. A trapezoid has only one pair of parallel sides while the other set of opposite sides are not parallel. Contrast this with a square which has 2 pairs of parallel opposite sides.
1b) False. A rhombus is only a rectangle when the figure is also a square. A square is essentially a rhombus and a rectangle at the same time. If you had a Venn Diagram, then the circle region "rectangle" and the circle region "rhombus" overlap to form the region for "square". If the statement said "sometimes" instead of "always", then the statement would be true.
1c) False. Any rhombus is a parallelogram. This can be proven by dividing up the rhombus into triangles, and then proving the triangles to be congruent (using SSS), then you use CPCTC to show that the alternate interior angles are congruent. Finally, this would lead to the pairs of opposite sides being parallel through the converse of the alternate interior angle theorem. Changing the "never" to "always" will make the original statement to be true. Keep in mind that not all parallelograms are a rhombus.
Answer:
24: x = 31
25: x = 15
Step-by-step explanation:
Remark
24 is supplementary which means that the two angles add to 180o which is on the right hand side of the equation
25 is complementary which means that the two angles add to 90o which is on the left hand side of the equation
Twenty Four
3x + 31 +2x - 6 = 180 Collect the like terms
3x +2x + 31 - 6 = 180 Do the adding and subtracting.
5x + 25 = 180 Subtract 25 from both sides
5x + 25 - 25 = 180 - 25
5x = 155 Divide by 5
x = 155/5
x = 31
Check
3x + 31 = 3*31 + 31
3x + 31 = 93 + 31
3x + 31 = 124
2x - 6 = 2*31 - 6 = 62 - 6 = 56
Total 124 + 56 = 180 as it should.
Twenty Five
Equation
3x+ 4x - 15 = 90
Solution
7x - 15 = 90 Like terms have been collected on the left.
7x = 90 + 15 15 was added to both sides
7x = 105 Divide by 7
x = 15 I'll leave the check to you
Answer: the square root of 3
Step-by-step explanation:
