Answer:
(4+8)(4) = (x) 3
Step-by-step explanation:
The picture shows two secants intersecting at a point outside the circle. A beautiful pattern for this is: along each secant, the product (multiply) the <em>entire</em> secant by the <em>outside</em> part is the same.
(entire secant)(outside part) = (entire secant)(ouside part)
(4+8)(4) = (x)(3)
Answer:
27 degrees
Step-by-step explanation:
The easy way is by remembering the formula (a-b)/2=c, where a is the larger angle, and b is the smallest angle. (90-36)/2=27.
The longer, more drawn out answer goes as follows. See the image to understand the notation I use:
- AOE + BOD + BOA + DOE = 360
- AOE + BOD = 90 + 36 = 126
- BOA + DOE = 360 - AOE - BOD = 234
- Since the sum of a triangle's angles is 180, ODE = (180 - DOE) / 2
- Likewise, OBA = (180 - BOA) / 2
- Since CDE is 180, CDO = 180 - ODE = 180 - (180 - DOE) / 2
- Likewise, CBA is 180, so CBO = 180 - OBA = 180 - (180 - BOA) / 2
- The interior angles of the irregular polygon CBOD add up to 360, so CBO + CDO + BOD + BCD = 360.
- Substituting what we already found, 180 - (180 - BOA)/2 + 180 - (180 - DOE)/2 + 36 + BCD = 360
- Cleaning it all up, we get 180 + (BOA + DOE)/2 + 36 + BCD = 360
- As we found in line 3, BOA + DOE = 234, so substituting that in, 180 + 117 + 36 + BCD = 360
- Finally, solving for BCD (360 - 36 - 117 - 180) we get our answer, 27
Note: The long drawn out method shown above is a way to derive the formula for the secant theorem. You do not need to use this method every time. Just remember, large angle minus small angle, all divided by 2. That is it.
25 miles per hour equals 11.176 meters per second.
Answer:
B: 192pi - 144
Step-by-step explanation:
Area of the sector = (120/360) * pi * r^2
Area of the sector = 1/3 * pi * 24 * 24
Area of the sector = 192 * pi
Now to find the area of the triangle.
The triangle is an isosceles triangle That means two of its sides are equal. They are equal to the radius of the circle, which is 24.
the small angles are equal to
2x + 120 = 180 Subtract 120 from both sides
2x = 60 Divide by 2
x = 60/2
x = 30
The height of the triangle is derived from sin(30) = opposite / hypotenuse
sin(30) = 1/2
hypotenuse = 24
1/2 = opposite / hypotenuse
1/2 = opposite / 24 Multiply both sides by 24
1/2 * 24 = opposite
opposite = 12
The height = 12
r = 24
Area of the triangle = 1/2 * 12 * 24
Area of the triangle = 144
So the area of the shaded area = 192*pi - 144 which looks like B