From the diagram;
1. Angle 2 = ADB+BDH
= arcAB/2 +90
= 34 +90
= 124°
2. Angle 4= 90°,
Reason ; the angle between a tangent and a radius is equal to 90. A tangent is a line that touches the circumference of a circle once even if prolonged.
3. Angle 5 = 90 -BDC (note the acr subtends twice the angle it subtends on the circumference to the center.
= 90-arc BC/2
= 90-36
= 54°
4. Angle 6 = BFD
= 180-ADB-FBD
= 180-AB/2-DE/2
But DE = 180 -121 = 59
Therefore, BFD = 180 -34-29.5
= 116.5°
5. Angle 1 = 180- BFD (angles on a straight line add up to 180°)
= 180- 116.5
= 63.5°
6. Angle 3 = 180 -(ADB+BFD)
= 180 -(34 +116.5)
= 180- 150.5
= 29.5°
similarly angle 3 = DE/2 = 59/2 = 29.5°
7. Angle 8= 90, because BD is diameter;
angles subtended by a diameter to the circumference is always a right angle (90°)
8.Angle 7 = BE
but BE= AB+AE
= 68+ 53
= 121°
4 because you would say "forty three thousand..." three would be the one thousands place, and 4 would be the ten thousands place.
First, we have
s1/r1 = s2/r2
The question also states the fact that
s/2πr = θ/360°
Rearranging the second equation, we have
s/r = 2πθ/360°
Then we substitute it to the first equation
s1/r1 = 2πθ1/360°
s2/r2 = 2πθ2/360°
which is now
2πθ1/360° = 2πθ2/360°
By equating both sides, 2π and 360° will be cancelled, therefore leaving
θ1 = θ2
Distance = speed x time
distance time
45 ft 3.0 s
87 ft 5.8 s
166.5 ft 11.1 s
210 ft 14.0 s
Answer:
16.2
Step-by-step explanation:
The angle internal to the triangle at B is the supplement of the one shown, so is 65°. That is equal to the angle internal to the triangle at D. Since the vertical angles at C are congruent, the two triangles are similar by the AA theorem.
Corresponding sides of similar triangles are proportional, so we can write the proportion shown in the attachment:
BC/FC = DC/AC
BC = FC(DC/AC) = 21.6(7.2/9.6)
BC = 16.2 . . . . matches the first choice
