Question

11. Find the co-ordinates of a point A where AB is the diameter of the circle with centre (-2, 2) and B is the
point with coordinates (3, 4).​

Answer 1

Answer:

circle with centre (2,−3) and AB is the diameter of circle with B(1,4).

To find:- Coordinate of point A.

Let (x,y) be the coordinate of A.

Since AB is the diameter of the circle, the centre will be the mid-point of AB.

now, as centre is the mid-point of AB.

x-coordinate of centre =

2

x+1

y-coordinate of centre =

2

y+4

But given that centre of circle is (2,−3).

Therefore,

2

x+1

=2⇒x=3

2

y+4

=−3⇒y=−10

Thus the coordinate of A is (3,−10).

Hence the correct answer is (3,−10).

Answer 2

Answer:

Width of rectangle is 25 cm.

Step-by-step explanation:

Given :-

A wire bend in form of square of side 30 cm.

Then wire is again bend in form of rectangle of length 35 cm.

To find :-

Width of the rectangle.

Solution :-

Here, Concept is : If we are bending wire in form of square than again bending it in rectangle. Than, perimeter of square will equal to perimeter of rectangle because we are not increasing length of wire by one measure we are bending it in square and rectangular shape.

So,

Perimeter of square = 4 × side

⟶ Perimeter = 4 × 30

⟶ Perimeter = 120

Thus,

Perimeter of square is 120 cm.

According to concept, Perimeter of square and perimeter of rectangle are equal.

So, Perimeter of rectangle is 120 cm.

Let, Breadth or width or rectangle be x cm.

We know,

Perimeter of rectangle = 2(Length + Breadth)

⟶ 120 = 2×(35 + x)

⟶ 120 = 70 + 2x

\⟶ 120 - 70 = 2x

⟶ 50 = 2x

⟶ 50/2 = x

⟶ x = 25

We take, Width of rectangle be x.

Therefore,

Width of rectangle is 25 cm.