Circumference: C=2pir
C stands for circumference. pi is 3.14... and r is the radius.
of course, you can always do, C=pid. where d is diameter because the radius is half the diameter
Area: A=pir^2
A stands for the Area, pi stands for 3.14... r stands for radius, and the little ^2 is the equation squared. The way to solve that is square the radius and then multiply what you got from squaring the radius by pi.
DO NOT replace radius with the diameter when trying to find the Area
Answer:
c = 27.9
B = 62.13°
C = 89.90°
Step-by-step explanation:
We are given the following values:
A= 121.59°, a = 27.9 cm, b = 52.6 cm
a) Finding side c
We would use Pythagoras Theorem
c² = a² + b²
c = √(a² + b²)
c = √(27.9² + 52.6²)
c = 59.54cm
≈ Approximately = 59.5cm
b) Finding B
We would be using Cosine rule to find Angle B
Cos B = a² + b² - c²/2ab
B = arc cos ( a² + c² - b²/2ac)
B = arc cos( 27.9² + 59.5² - 52.6²/ 2 × 27.9 × 59.5)
B = 62.13268°
B = 62.13°
c) Finding C
We would be using Cosine rule to find Angle C
Cos C = a² + b² - c²/2ab
C = arc cos ( a² + b² - c²/2ab)
C = arc cos( 27.9² + 52.6² - 59.5²/ 2 × 27.9 × 52.6)
C = 89.9°
Two lines are parallel if the gradient (i.e. the x coefficient) of them both is the same.
Two lines are perpendicular if the gradient has its sign changed
and has it's fraction flipped (i.e. a gradient of 2/3 would become -3/2, and a gradient of 10 would become -1/10)
THe first one is in the correct form already, with a gradient of -4.
Now we need to rearrange the second:

The second equation has a gradient of 1/4, which is indeed the negative and reversal of -4, therefore the two lines are
perpendicular.
Answer:Find the area of an equilateral triangle with radius 8. m.
Step-by-step explanation:
Answer:
54mph
Step-by-step explanation:
To find the speed in "miles per hour" or miles/hour, divide the number of miles by number of hours.
1080 miles/20 hours
= 54miles/hour
His speed is 54 miles per hour.