Formula of the area of triangle
A=(1/2)a*b*sin(C)
a, b - sides
C- an angle between sides a and b.
Probably, this question means that you need to know sin of the angle.
The formula for perimeter is:
<span>P = 2 h + 2 w</span>
where P is perimeter = 120 cm, h is height, w is width
we are also given that: h = (2/3) w, therefore:
P = 2 (2/3) w + 2 w = 120
(4/3) w + 2 w = 120
w = 36 cm
Therefore l is:
l = (2/3) w = 24 cm
<span>Hence the dimension should be 24cm by 36 cm</span>
Let the number of bike be x and the number of skates be y, then
21x + 20y ≥ 362 . . . (1)
2y = x . . . (2)
Putting (2) into (1), then
21(2y) + 20y ≥ 362
42y + 20y ≥ 362
62y ≥ 362
y ≥ 5.84
The least number of pairs of skates they need to rent each day to make their minimum is 6.
The given equation is,

It can be rewritten in the form of y=mx+c, where c is the y intercept.
Hence,

Put different values for x and find value of y.
When x=0, y=1.
When x=1,

The graph is,