We are given the coordinate of the 3 vertices. From these coordinates we can find the length of the sides using the distance formula and the sum of all the sides will be equal to the perimeter of the triangle.
Side PQ =

Side QR =

Side RP =

So, the perimeter of the triangle will be 8 + 4.5 + 7.2 = 19.7
You probably misplaced the digits in option A. The correct answer is 19.7 units.
It is not possible to select a single group from the primary school, since being a single group it could not in any way represent the entire primary school.
Choosing a group would provide the average height for that group, not the entire primary.
Assumptions can be made that the course of half of the primary would theoretically give us a more accurate representation, but the objective is to select a number of students from each course and there would be a representative sample of the entire primary.
Answer:
2/5
Step-by-step explanation:
![\frac{\sqrt[3]{8} }{\sqrt[3]{125} } = \frac{2}{5}](https://tex.z-dn.net/?f=%5Cfrac%7B%5Csqrt%5B3%5D%7B8%7D%20%7D%7B%5Csqrt%5B3%5D%7B125%7D%20%7D%20%20%3D%20%5Cfrac%7B2%7D%7B5%7D)
Answer:
9 tens and 6 ones
Step-by-step explanation:
9 is in the tens spot and 6 is in the ones spot