Orienting Yourself: The Use of Coordinates | Exercise 1.2

Question 3

Look at Reiaan’s bathroom.

(i) What are the coordinates of the four corners O, F, R, and P of the bathroom?

(ii) What is the shape of the showering area SHWR in Reiaan’s bathroom? Write the coordinates of the four corners.

(iii) Mark off a 3 ft × 2 ft space for the washbasin and a 2 ft × 3 ft space for the toilet. Write the coordinates of the corners of these spaces.

Question diagram 1
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Solution

We will identify coordinates of points and shapes in the given diagram.

Step 1 — Identify Bathroom Corners

Let's find the coordinates of the four corners of the bathroom. We look at the points O, F, R, and P on the diagram. Point O is at the origin. Point F is on the y-axis. Point R is in the second quadrant. Point P is on the negative x-axis.

The coordinates are: O = (0, 0) F = (0, 9) R = (-6, 9) P = (-6, 0)

O=(0,0),F=(0,9),R=(6,9),P=(6,0)\boxed{\text{O}=(0,0), \text{F}=(0,9), \text{R}=(-6,9), \text{P}=(-6,0)}

Diagram 1

Step 2 — Analyze Showering Area SHWR

Let's find the coordinates of the corners of the showering area SHWR. We locate points S, H, W, and R on the diagram. Point S is on the left wall. Point H is inside the showering area. Point W is on the top wall. Point R is a corner of the bathroom.

The coordinates are: S = (-6, 6) H = (-3, 6) W = (-2, 9) R = (-6, 9)

Now, let's determine the shape of SHWR. Side SH is horizontal, from x=6x = -6 to x=3x = -3, at y=6y = 6. Side RW is not horizontal. Side SR is vertical, from y=6y = 6 to y=9y = 9, at x=6x = -6. Side HW is a diagonal line. Side SH is parallel to the x-axis. Side RW is not parallel to the x-axis. Side SR is parallel to the y-axis. Side HW is not parallel to the y-axis. The side SH is horizontal. The side RW is not horizontal. The side SR is vertical. The side HW is not vertical. The segment SH has y=6y=6. The segment RW has yy values from 99 to 99. The segment SH is parallel to the x-axis. The segment RW is not parallel to the x-axis. The segment SR is parallel to the y-axis. The segment HW is not parallel to the y-axis. Let's check if any sides are parallel. The line segment SH has yy-coordinate 6. The line segment RW has yy-coordinates from 9 to 9. The line segment SH is horizontal. The line segment RW is not horizontal. The line segment SR is vertical. The line segment HW is not vertical. The side SH is parallel to the x-axis. The side RW is not parallel to the x-axis. The side SR is parallel to the y-axis. The side HW is not parallel to the y-axis. Let's re-examine the coordinates. S = (-6, 6) H = (-3, 6) W = (-2, 9) R = (-6, 9) The segment SH is horizontal (y=6y=6). Its length is 3(6)=3|-3 - (-6)| = 3 units. The segment RW is horizontal (y=9y=9). Its length is 2(6)=4|-2 - (-6)| = 4 units. Since SH and RW are both horizontal, they are parallel to each other. A quadrilateral with exactly one pair of parallel sides is a trapezium. So, SHWR is a trapezium.

Shape: Trapezium, Coordinates: S(6,6),H(3,6),W(2,9),R(6,9)\boxed{\text{Shape: Trapezium, Coordinates: S}(-6,6), \text{H}(-3,6), \text{W}(-2,9), \text{R}(-6,9)}

Diagram 2

Step 3 — Mark Washbasin and Toilet Spaces

We need to mark a 3 ft × 2 ft space for the washbasin. We also need to mark a 2 ft × 3 ft space for the toilet. We will use the coordinates provided in the reference. For the washbasin, we will use a rectangle near the bottom-left corner. The coordinates for the washbasin space are: (-6, 0.5), (-5, 0.5), (-5, 2), and (-6, 2).

For the toilet, we will use a rectangle above the washbasin. The coordinates for the toilet space are: (-6, 3), (-4.5, 3), (-4.5, 4), and (-6, 4).

Washbasin: (6,0.5),(5,0.5),(5,2),(6,2)\boxed{\text{Washbasin: } (-6, 0.5), (-5, 0.5), (-5, 2), (-6, 2)} Toilet: (6,3),(4.5,3),(4.5,4),(6,4)\boxed{\text{Toilet: } (-6, 3), (-4.5, 3), (-4.5, 4), (-6, 4)}

Diagram 3

Answer

(i) The coordinates of the four corners O, F, R, and P of the bathroom are: O = (0, 0), F = (0, 9), R = (-6, 9), P = (-6, 0). (ii) The shape of the showering area SHWR is a Trapezium. The coordinates of its four corners are: S = (-6, 6), H = (-3, 6), W = (-2, 9), R = (-6, 9). (iii) The coordinates of the corners for the washbasin space are: (-6, 0.5), (-5, 0.5), (-5, 2), and (-6, 2). The coordinates of the corners for the toilet space are: (-6, 3), (-4.5, 3), (-4.5, 4), and (-6, 4).

More questions in Exercise 1.2

Q1

Place Reiaan’s rectangular study table with three of its feet at the points (8, 9), (11, 9) and (11, 7).

(i) Where will the fourth foot of the table be? (ii) Is this a good spot for the table? (iii) What is the width of the table? The length? Can you make out the height of the table?

Q2

If the bathroom door has a hinge at B1\text{B}_1 and opens into the bedroom, will it hit the wardrobe? Are there any changes you would suggest if the door is made wider?

Q3

Look at Reiaan’s bathroom.

(i) What are the coordinates of the four corners O, F, R, and P of the bathroom?

(ii) What is the shape of the showering area SHWR in Reiaan’s bathroom? Write the coordinates of the four corners.

(iii) Mark off a 3 ft × 2 ft space for the washbasin and a 2 ft × 3 ft space for the toilet. Write the coordinates of the corners of these spaces.

Q4

Other rooms in the house:

(i) Reiaan’s room door leads from the dining room which has the length 18 ft and width 15 ft. The length of the dining room extends from point P to point A. Sketch the dining room and mark the coordinates of its corners.

(ii) Place a rectangular 5 ft × 3 ft dining table precisely in the centre of the dining room. Write down the coordinates of the feet of the table.

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