Q1. Determine the ratio in which the line 2x + y – 4 = 0 divides the line segment joining the points A(2, – 2) and B(3, 7)

Solution 1

Q2. Find a relation between x and y if the points (x, y), (1, 2) and (7, 0) are collinear.

Solution 2.

Q3. Find the centre of a circle passing through the points (6, – 6), (3, – 7) and (3, 3).

Solution 3.

Q4. The two opposite vertices of a square are (–1, 2) and (3, 2). Find the coordinates of the other two vertices.

Solution 4

Q5. The Class X students of a secondary school in Krishinagar have been allotted a rectangular plot of land for their gardening activity. Sapling of Gulmohar are planted on the boundary at a distance of 1m from each other. There is a triangular grassy lawn in the plot as shown in the Fig.. The students are to sow seeds of flowering plants on the remaining area of the plot.

(i) Taking A as origin, find the coordinates of the vertices of the triangle.

(ii) What will be the coordinates of the vertices of ∆ PQR if C is the origin? Also calculate the areas of the triangles in these cases. What do you observe?

(i) Taking A as origin, find the coordinates of the vertices of the triangle.

(ii) What will be the coordinates of the vertices of ∆ PQR if C is the origin? Also calculate the areas of the triangles in these cases. What do you observe?

Solution 5

Q6. The vertices of a ∆ABC are A(4, 6), B(1, 5) and C(7, 2). A line is drawn to intersect sides AB and AC at D and E respectively, such that `frac{AD}{AB}=frac{AE}{AC}=frac{1}{4}`⋅ Calculate the area of the ∆ ADE and compare it with the area of ∆ABC. (Recall Theorem 6.2 and Theorem 6.6).

Solution 6

Q7. Let A (4, 2), B(6, 5) and C(1, 4) be the vertices of ∆ABC.

(i) The median from A meets BC at D. Find the coordinates of the point D.

(ii) Find the coordinates of the point P on AD such that AP : PD = 2 : 1

(iii) Find the coordinates of points Q and R on medians BE and CF respectively such that BQ : QE = 2 : 1 and CR : RF = 2 : 1.

(iv) What do yo observe? [Note : The point which is common to all the three medians is called the centroid and this point divides each median in the ratio 2 : 1.]

(v) If A(x 1 , y 1 ), B(x 2 , y 2 ) and C(x 3 , y 3 ) are the vertices of ∆ABC, find the coordinates of the centroid of the triangle.

(i) The median from A meets BC at D. Find the coordinates of the point D.

(ii) Find the coordinates of the point P on AD such that AP : PD = 2 : 1

(iii) Find the coordinates of points Q and R on medians BE and CF respectively such that BQ : QE = 2 : 1 and CR : RF = 2 : 1.

(iv) What do yo observe? [Note : The point which is common to all the three medians is called the centroid and this point divides each median in the ratio 2 : 1.]

(v) If A(x 1 , y 1 ), B(x 2 , y 2 ) and C(x 3 , y 3 ) are the vertices of ∆ABC, find the coordinates of the centroid of the triangle.

Solution 7

Q8. ABCD is a rectangle formed by the points A(–1, –1), B(– 1, 4), C(5, 4) and D(5, – 1). P, Q, R and S are the mid-points of AB, BC, CD and DA respectively. Is the quadrilateral PQRS a square? a rectangle? or a rhombus? Justify your answer.

Solution 8

**‹Exercise 7.3 Exercise 8.1›**