Answer:
Q7. 11.3 inches (3 s.f.)
Q8. 96.2 ft
Q9. 36.4cm
Step-by-step explanation:
Q7. Please see attached picture for full solution.
Q8. Let the length of a side of the square be x ft.
Applying Pythagoras' Theorem,

Thus, the perimeter of the square is

Q9. Equilateral triangles have 3 equal sides and each interior angle is 60°.
Since the perimeter of the equilateral triangle is 126cm,
length of each side= 126÷3 = 42 cm
The green line drawn in picture 3 is the altitude of the triangle.
Let the altitude of the triangle be x cm.
sin 60°= 
(to 3 s.f.)
Therefore, the length of the altitude of the triangle is 36.4cm.
The reference angle is
pi/3.
At 180 it would be 9pi/3 so going past that is 10pi/3.
Answer:
5r + 3s ≥ 30
Step-by-step explanation:
We know Keiko wants to do exercise at least 30 minutes a day, and she wants ideally to mix up the activities, by combining running and swimming into her schedule.
Since each lap she runs takes 5 minutes and each lap she swims takes 3 minutes, these will be the left side of the inequality:
5r + 3s
She wants to exercise at least 30 minutes a day, so...
5r + 3s ≥ 30
she could do 3 laps of running and 5 laps of swimming for example.
There are multiple ways in which Anita can divide the sheet of paper for her calendar. First she can have it halved first then, divided by 6 or she can have it divided by 4 and divided each quarter by 3. Either way, each month would take up 1/12 of the total area of the paper.