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## Tamilnadu Samacheer Kalvi 9th Maths Solutions Chapter 7 Mensuration Ex 7.1

**9th Maths Mensuration Exercise 7.1 Question 1.**

Using Heron’s formula, find the area of a triangle whose sides are

(i) 10 cm, 24 cm, 26 cm

(ii) 1.8 m, 8 m, 8.2 m

Solution:

(i) sides : 10 cm, 24 cm, 26 cm

Using Heron’s formula

Area of the triangle = \(\sqrt{s(s-a)(s-b)(s-c)}\) sq. units

**9th Maths Mensuration Question 2.**

The sides of the triangular ground are 22 m, 120 m and 122 m. Find the area and cost of leveling the ground at the rate of ₹ 20 per m^{2}.

Solution:

**9th Maths Book Mensuration ex 7.1 Question 3.**

The perimeter of a triangular plot is 600 m. If the sides are in the ratio 5 : 12 : 13, then find the area of the plot.

Solution:

s = 600 m

Side s are in the ratio 5 : 12 : 13

5x + 12x + 13x = 30x

∴ sides are 200 m, 480 m, 520 m.

**9th Maths 7.1 Mensuration Question 4.**

Find the area of an equilateral triangle whose perimeter is 180 cm.

Solution:

Perimeter of an equilateral triangle = 180 cm

**9th Maths Exercise 7.1 Question 5.**

An advertisement board is in the form of an isosceles triangle with perimeter 36m and each of the equal sides are 13 m. Find the cost painting it at ₹ 17.50 per square metre.

Solution:

Cost of painting 1 m^{2} = ₹ 17.50

Cost of painting 60m^{2} = 60 × 17.50 = ₹ 1050

**Samacheer Kalvi 9th Maths Guide Question 6.**

Find the area of the unshaded region.

Solution:

**Exercise 7.1 Class 10 Samacheer Kalvi Question 7.**

Find the area of a quadrilateral ABCD whose sides are AB = 13 cm, BC = 12 cm, CD = 9 cm, AD = 14 cm and diagonal BD = 15 cm

Solution:

**Samacheer Kalvi 9th Maths Book Solutions Question 8.**

A park is in the shape of a quadrilateral. The sides of the park are 15 m, 20m, 26 m and 17 m and the angle between the first two sides is a right angle. Find the area of the park.

Solution:

**Samacheer Kalvi Guru 9th Maths Guide Question 9.**

A land is in the shape of rhombus. The perimeter of the land is 160 m and one of the diagonal is 48 m. Find the area of the land.

Solution:

Perimeter of the rhombus land = 160 m

**Exercise 7.1 Class 9 Question 10.**

The adjacent sides of a parallelogram measures 34 m, 20 m and the measure of the diagonal is 42 m. Find the area of Parallelogram.

Solution: