Chapter 12 Heron’s Formula- MCQ Online Test 1 Class 9 Maths

1. The area of a triangle with base 8 cm and height 10 cm is
(a) 42 cm²
(b) 41 cm²
(c) 35 cm²
(d) 40 cm²

2. The sides of a triangle are in the ratio of 3 : 4 : 5. If its perimeter is 36 cm, then what is its area?
(a) 54 cm²
(b) 72 cm²
(c) 60 cm²
(d) 45 cm²

3. An isosceles right triangle has area 8 cm². The length of its hypotenuse is
(a) √16 cm
(b) √32 cm
(c) √24cm
(d) √28cm

4. The cost of turfing a triangular field at the rate of Rs. 45 per 100 m² is Rs. 900. If the double the base of the triangle is 5 times its height, then its height is
(a) 32 cm
(b) 44 cm
(c) 40 cm
(d) 34 cm

5. The base of a right triangle is 8 cm and hypotenuse is 10 cm. Its area will be
(a) 24 cm²
(b) 28 cm²
(c) 30 cm²
(d) 44 cm²

6. The area of a triangle whose sides are 12 cm, 16 cm and 20 cm is
(a) 96 cm²
(b) 105 cm²
(c) 120 cm²
(d) 112 cm²

7. The difference of semi-perimeter and the sides of △ABC are 8, 7 and 5 cm respectively. Its semi-perimeter ‘s’ is
(a) 30 cm
(b) 20 cm
(c) 18 cm
(d) 25 cm

8. The sides of a triangle are 56 cm, 60 cm and 52 cm long. Then the area of the triangle is
(a) 1344 cm²
(b) 1323 cm²
(c) 1401 cm²
(d) 1329 cm²

9. The sides of a triangular flower bed are 5 m, 8 m and 11 m. the area of the flower bed is
(a) 3√34 m²
(b) 4√21 m²
(c) 6√11 m²
(d) √141 m²

10. A triangle ABC in which AB = AC = 4 cm and ∠A = 90°, has an area of
(a) 15 cm²
(b) 18 cm²
(c) 12 cm²
(d) 8 cm²