Area, circumference, trig, Pythagoras

Question 1

what is the equation for the cosine rule

Answer 1

a²=b²+c²-2bc CosA

Question 2

when is sine rule used

Answer 2

when you are given 2 sides and an angle not between them or given 2 angles and 1 side

opposite angles and sides go together

Question 3

Equation for sine rule

Answer 3

a/SinA= b/SinB= c/SinC

Question 4

rearranged equation to get an angle using the cosine rule

Answer 4

CosA=(b²+c²-a²)/2bc

Question 5

how to know if triangles are congruent

Answer 5

they share, ASA, SAS or SSS

Question 6

when is the cosine rule used

Answer 6

when you are given 3 sides and trying to find an angle or when you are given 2 sides and an angle between, looking for the opposite side

Question 7

how to find area of non-right angle triangle

Answer 7

1/2 bcSinA

Question 8

how to switch between degree and radian mode

Answer 8

shift-> setup-> 4

Question 9

what is a radian

Answer 9

the angle value for when the radius is equal to the arc length of a sector

Question 10

how to convert degrees into radian

Answer 10

X°/360 *2π

Question 11

how to convert radian into degrees

Answer 11

Xrad/2π *360

Question 12

how to find area of a sector (rad)

Answer 12

(θ/2)r²

Question 13

how to find area of sector (degrees)

Answer 13

πr²* x/360

Question 14

how to find arc length of sector (rad)

Answer 14

θr

theta * radius

Question 15

how to find arc length of sector (deg)

Answer 15

πd*x/360

Question 16

convert πrad into deg

Answer 16

(π/2π) *360= 180°

Question 17

convert π/5 rad into deg

Answer 17

(π/5)/2π *360= 36°

Question 18

convert 60° into radian

Answer 18

60/360 *2π= π/3rad