NCERT Mathematics Class 9 Exemplar Ch 12 Heron's Formula Part 1

Exercise 12.1

1. An isosceles right triangle has area. The length of its hypotenuse is

(A)

(B)

(C)

(D)

Answer: A

2. The perimeter of an equilateral triangle is 60 m. The area is

(A)

(B)

(C)

(D)

Answer: D

3. The sides of a triangle are 56 cm, 60 cm and 52 cm long. Then the area of the triangle is

(A)

(B)

(C)

(D)

Answer: C

4. The area of an equilateral triangle with side cm is

(A)

(B)

(C)

(D)

Answer: A

5. The length of each side of an equilateral triangle having an area of is

(A)

(B)

(C)

(D)

Answer: D

6. If the area of an equilateral triangle is , then the perimeter of the triangle is

(A)

(B)

(C)

(D)

Answer: B

7. The sides of a triangle are , and , respectively. The length of its longest altitude

(A)

(B)

(C)

(D)

Answer: C