Question

help me with this question

English and Malay version is provided at the question

Answer 1

(a)
solution:-
Here,
r = j
OA= OB=j
angle OAB = theta
so,
area of sector/area of circle = theta/360------(1)
length of Arc/ length of circumference= theta/360-------(2)
From equipment (1) and (2), we get
length of area/length of circumference = area of sector/area of circle
(2πr * theta/360)/2πr = (πr² * theta/360)/πr² = theta/360
Now,
length of Arc= 2πr * theta/360
= 2 * π * j * theta/360
= πj* theta/180 -----------(3)
Now, according to question, it is given that
theta = 80°
radius = 9 cm
π = 3.142
so,
length of Arc = 3.142 * 80 * 9/180 [From equation 3]
= 12.568 cm
Hence, length of Arc in terms of j, π and theta is πj*theta/180 and the length of Arc according to given value is 12.568 cm.
(b)
Solution:-
area of minor sector = πr² * theta/360
= πj²*theta/360------(4)
Now according to question, we have
π = 22/7
j = 7 cm
theta = 60
Now,
area of minor sector = πj²*theta/360 [From equation 4]
=(22/7 * 60)/360
= 25.6 cm²
Hence, area of sector in term of theta, j and π is πr²*theta/360 and area of the sector according to given value is 25.6 cm².

Answer 2

Answer:

ans....25.6............... ok.......