Question

Area of a right angled triangle is 54 cm square.
if one of its leg is 12cm long then what will be the perimeter?

Answer 1

Answer:

Area = 1/2 x base x height

54 = 1/2 x 12 x h

h = 54 x 2 x 1/12

h = 9 cm

Step-by-step explanation:

Answer 2

Given:-

• Area of a right angled triangle is 54 cm square.
• One of its leg is 12 cm long.

To find:-

• Perimeter of a right angled triangle.

Solution:-

We know that

→ Area of right angled triangle = 1/2 × b × h

→ 1/2 × b × h = 54

• Taking base as 12 cm we get

→ 1/2 × 12 × height = 54

→ 6 × height = 54

→ height = 54/6

→ height = 9 cm

Now,

→ Hypotenuse² = base² + height²

→ Hypotenuse² = 12² + 9²

→ Hypotenuse² = 144 + 81

→ Hypotenuse² = 225

→ Hypotenuse = √225

→ Hypotenuse = 15 cm

Then,

→ Perimeter = sum of all sides

→ Perimeter = 12 + 9 + 15

→ Perimeter = 36 cm

Hence,

• the perimeter of a right angled triangle is 36 cm.