formulas

Question 1

area of a full circle

Answer 1

πr^2

Question 2

area of a semi circle

Answer 2

πr^2
——
2

Question 3

area of a quadrant

Answer 3

πr^2
——
4

Question 4

area of a triangle

Answer 4

base x perpendicular height
——————————
2

Question 5

area of a trapezium

Answer 5

(a + b) x height
———————
2

Question 6

area of a sector

Answer 6

(πr^2) x (θ ÷ 360)

Question 7

volume of a pyramid / cone

Answer 7

(area of base) x height
——————————-
3

Question 8

volume of a sphere

Answer 8

4
—— x πr^3
3

Question 9

volume of a prism

Answer 9

cross sectional area x length

Question 10

volume of a cylinder

Answer 10

πr^2 x height

Question 11

perimeter of a semi circle

Answer 11

(πd ÷ 2) + d

Question 12

perimeter of a sector

Answer 12

(πd) x (θ ÷ 360) + d

Question 13

perimeter of a quadrant

Answer 13

(πd ÷ 4) + d

Question 14

circumference of a circle

Answer 14

πd

Question 15

arc length

Answer 15

πd x (θ ÷ 360)

Question 16

midpoints of a line

Answer 16

(x1 + x2 , y1 + y2)
——— ———
2 2

Question 17

finding the distance between two coordinates / length of a line segment

Answer 17

√(x2 - x1)^2 + (y2 - y1)^2

Question 18

equation of a line

Answer 18

y=mx+c

Question 19

gradient of a line

Answer 19

rise / run or y2 - y1
———
x2 - x1

Question 20

what is the cosine formula for missing lengths?

Answer 20

a^2 = b^2 + c^2 - 2bccosA

Question 21

what is the cosine formula for missing angles?

Answer 21

cos^-1 (b^2 + c^2 - a^2 / 2bc)