Answer:

Step-by-step explanation:
because you are finding the total they both had in September, you add. 12 + 9 = 21
We know that AB is perpendicular to CD. (that was given)
Perpendicular angles are 90 degrees because two straight lines (180) crossed make 4 90 degree angles.
180+180=360
90*4=360 See the similarities?
7x+6= 90 degrees
Subtract 6 on both sides.
7x=84
Divide both sides by 7.
x=12
"B" is the correct answer.
I hope this helps!
~kaikers
Answer:
x=90°
y=55°
Step-by-step explanation:
A
D
C
B
let the triangle be named ABD
angleABD= 1/2 angleACD[ being angle formed at same
] arc
=1/2×180
= 90
now,
angleX + angleY + 35° = 180 [ sum of the angle
of the triangle]
90 + Y + 35 = 180
Y= 180-125
Y = 55
Do you remember your unit circle? If sin ω = was -1/2, then it would be 7<span>π/6. If you're unfamiliar with the unit circle, we can derive it.
So, you know that sin is OPPOSITE/HYPOTENUSE, and it's in the third quadrant, where x and y would be negative. If sin </span>ω = -1/2, that means that ω = 1/sin*(-1/2), or sin^(-1)*(-1/2). Let's ignore the negative for now and plug sin^(-1)*(-1/2) into your calculator in radians. You get (1/6)π. But that's in Quadrant 1. We want it in Quadrant 3.
In one complete revolution, or 360°, there are 2π radians. That means, if you want to rotate it 180°, you need to add π to what you originally got.
π+(1/6)π=(7/6)π.
I highly recommend you memorize the unit circle if you haven't already, because you'll need it from Precalculus on.