chap 12 ( perimeter & plabe figures)

how to convert from square metre to square centimetre.

1. convert 1 m to cm. 2. find 1 square metre in terms of square centimetre by squaring both sides. 3. find the required square centimetre by multiplying the number to the right-hand side of the equation.

how to convert from square centimetre to square metre

1. convert 1 centimetre to metre. 2. find 1 square centimetre in terms of square metre by squaring both sides. 3. find the required square centimetre by multiplying the number to the right-hand side of the equation.

what is the formula to finding the perimeter/circumference of a circle?

(pi)(d) OR (2)(pi)(r)

what is the formula to finding the area of a circle?

(pi)(r)square

what to take note of when finding the perimeter of a semicircle/quarter of a circle?

add the length of the straight line(s)

qns: given that BD is perpendicular to AC, find the length of BD.

Length of BD: 252 square centimetres / 30 cm = 8.4 cm

take note

what is the formula to find the area of a parallelogram?

base x height

what is another way to find the area of a rhombus without multiplying its base and height

1/2 x length of diagonal 1 x length of diagonal 2

take note

what is the formula to finding the area of a trapezium

1/2 x (a+b) x height

when the decimal is about 3/4 decimal places but is terminating, what decimal place do we round it off to?

DO NOT round off and leave it as it is as the answer as it is a terminating decimal.