class 9 ncert ganit manjari math solution Exercise Set 1.1

Class 9 Maths · Ganita Manjari · Exercise Set 1.1

(i)

If D₁R₁ represents the door to Reiaan’s room, how far is the door from the left wall (the y‑axis) of the room? How far is the door from the x‑axis?

The door lies along the x‑axis, so its distance from the x‑axis is 0 units.

From the figure, D₁ = (8, 0) and R₁ = (11.5, 0).

Therefore, the door begins 8 units from the y‑axis (the left wall).

(ii)

What are the coordinates of D₁?

The coordinates of D₁ are (8, 0).

(iii)

If R₁ is the point (11.5, 0), how wide is the door? Do you think this is a comfortable width for the room door? If a person in a wheelchair wants to enter the room, will she/he be able to do so easily?

Coordinates of D₁ = (8, 0) and R₁ = (11.5, 0).

So, the width of the door = distance between D₁ and R₁ = 11.5 – 8 = 3.5 units.

If one unit represents one foot, then 3.5 ft ≈ 42 inches, which is a comfortable width for a room door. Standard residential doors are usually 30–36 inches wide, so this door is slightly wider than average, which is beneficial.

For wheelchair accessibility, a wheelchair typically requires a clear width of at least 32 inches (about 2.7 ft). Since 3.5 ft is greater than 2.7 ft, the door is wide enough. Therefore, the door is comfortable in size and a person in a wheelchair can enter easily.

(iv)

If B₁ (0, 1.5) and B₂ (0, 4) represent the ends of the bathroom door, is the bathroom door narrower or wider than the room door?

Coordinates of B₁ = (0, 1.5) and B₂ = (0, 4).

So, the width of the bathroom door = distance between B₁ and B₂ = 4 – 1.5 = 2.5 units.

Since 2.5 < 3.5, the bathroom door is narrower than the room door.

Room door

3.5 units

Bathroom door

2.5 units

class 9 ncert ganit manjari math solution Exercise Set 1.1

Exercise Set 1.1 Class 9 · Ganita Manjari

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