Question

❖ᴏɴʟʏ ᴘʀᴏᴘᴇʀ ꜱᴏʟᴠᴇᴅ ᴀɴꜱᴡᴇʀ ᴡɪᴛʜ ɢᴏᴏᴅ ᴇxᴘʟᴀɴᴀɪᴏɴ ɴᴇᴇᴅᴇᴅ
❖ ɴᴏ ꜱᴘᴀᴍᴍɪɴɢ
❖ᴏɴʟʏ ꜰᴏʀ ᴍᴏᴅᴇʀᴀᴛᴏʀꜱ, ʙʀᴀɪɴʟʏ ꜱᴛᴀʀꜱ ᴀɴᴅ ᴏᴛʜᴇʀ ʙᴇꜱᴛ ᴜꜱᴇʀꜱ​​​​​​​​​​​​​​​​​

Answer 1

Answer :

Let the sides of triangle be 3x, 4x, 5x.

Perimeter = 36 cm²

⇒ 3x + 4x + 5x = 36

⇒ 12x = 36

⇒ x = 36/12

∴ x = 3.

Sides,

• 3x (a) = 9 cm
• 4x (b) = 12 cm
• 5x (c) = 15 cm

Semiperimeter (s)= 36/2 = 18 cm

Using Heron's Formula,

= √[s(s - a)(s - b)(s - c)]

= √[18(18 - 9)(18 - 12)(18 - 15)]

= √[18 × 9 × 6 × 3]

= √[2916]

= 54

Area = 54 cm².

Answer is option (b). ✔