12. Heron’s Formula Class 9 Mathematics NCERT Exemplar Solutions (CBSE)

Chapter 12: Heron’s Formula – Class 9 Mathematics NCERT Exemplar Solutions (CBSE Board)

Chapter 12: Heron’s Formula

EXERCISE 12.1
1. An isosceles right triangle has area 8 cm² . The length of its hypotenuse is
(A) 32 cm (B) 16 cm (C) 48 cm (D) 24 cm

2. The perimeter of an equilateral triangle is 60 m. The area is
(A) 103 m²  (B) 153 m²  (C) 203 m²  (D) 1003 m²
3. The sides of a triangle are 56 cm, 60 cm and 52 cm long. Then the area of the triangle is
(A) 1322 cm²  (B) 1311 cm²  (C) 1344 cm²  (D) 1392 cm²
4. The area of an equilateral triangle with side 23 cm is
(A) 5.196 cm²  (B) 0.866 cm²  (C) 3.496 cm²  (D) 1.732 cm² 
5. The length of each side of an equilateral triangle having an area of 93 cm²  is
(A) 8 cm (B) 36 cm (C) 4 cm (D) 6 cm
6. If the area of an equilateral triangle is 163 cm² , then the perimeter of the triangle is
(A) 48 cm (B) 24 cm (C) 12 cm (D) 36 cm
7. The sides of a triangle are 35 cm, 54 cm and 61 cm, respectively. The length of its longest altitude
(A) 165 cm (B) 105 cm (C) 245 cm (D) 28 cm
8. The area of an isosceles triangle having base 2 cm and the length of one of the equal sides 4 cm, is
(A) 2 15 cm (B) 215 cm 2 (C) 22 15 cm (D) 24 15 cm
9. The edges of a triangular board are 6 cm, 8 cm and 10 cm. The cost of painting it at the rate of 9 paise per cm 2 is
(A) Rs 2.00 (B) Rs 2.16 (C) Rs 2.48 (D) Rs 3.00

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Posted 4 months ago