Step-by-step explanation:
Sn=n/2(2a+(n-1)d)
910=n/2{2a+(n-1)d}
1820=n{2a+(n-1)d}
1820=20{2a+(20-1)d}
1820=20{2a+19d}
91=2a+19d
An=a+(n-1)d
95=a+(20-1)d
95=a+19d
91=2a+19d
---------------
4=-a
a=-4
91=2a+19d
91=2(-4)+19d
91=-8+19d
91+8=19d
99=19d
d=99/19
A=-4
Answer:
Vertical angles are always congruent.
Step-by-step explanation:
Vertical angles are formed when two straight lines intersect each other, thereby forming two pairs of opposite angles, which are called vertical angles. Thus, a pair of these vertical angles formed are congruent to each other. So therefore, if two angles are said to be vertical angles, it follows that they are congruent to each other.
Using the diagram attached below, we can see two straight lines intersecting each other to form two pairs of vertical angles:
<a and <b,
<c and <d.
Thus, <a is congruent to <b, and <c is congruent to <d.
Therefore, the standby that is true about vertical angles is that:
Vertical angles are always congruent.
Answer:
630m³
Step-by-step explanation:
volume= 7m×9m×10m=630m³
Answer:
12.9 yd
Step-by-step explanation:
It helps if you draw a triangle. Draw a horizontal segment. That is the ground. Now at the left end start a new segment that goes up to the right at approximately 15 degrees until it its other endpoint directly above the right endpoint of the horizontal segment. Connect these two endpoints. The vertical side on the right shows the height of the kite. The hypotenuse is the string.
For the 15-deg angle, the height of the triangle is the opposite leg, and the string is the hypotenuse. The trig ratio that relates the opposite leg tot he hypotenuse is the sine.




