Question

9- Two sides of a triangle are 25 cm and 21 cm. The perimeter of the triangle is
75 cm. What will be the length of the third side ?​

Answer 1

G I V E N :

• Two sides of a triangle are 25 cm and 21 cm. The perimeter of the triangle is
• 75 cm.

TO F I N D :

• The third side of triangle = ?

S O L U T I O N :

• Perimeter of triangle = 75 cm
• Two sides of triangle = 25 cm and 21 cm

Let the third side of triangle be 'x' cm.

★ According to Question now :

→ Perimeter of triangle = Sum of all sides of triangle

→ 75 = 25 + 21 + x

→ 75 = 46 + x

→ 75 - 46 = x

→ 29 = x

→ x = 29 cm

Hence, the third side of triangle is 29 cm.

⠀⠀━━━━━━━━━━━━━━━━━━━━

★ V E R I F I C A T I O N :

➻ 75 = 25 + 21 + x

➻ 75 = 25 + 21 + 29

➻ 75 = 75

► LHS = RHS ◄

Hence Verified !

⠀⠀━━━━━━━━━━━━━━━━━━━━

E X T R A S H O T S :

• Area of right angled triangle = 1/2 × b × h
• Area of triangle using Heron's formula = √s(s - a)(s - b)(s - c)

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Answer 2

$\huge{\boxed{\rm{\red{Question}}}}$

Two sides of a triangle are 25 cm and 21 cm. The perimeter of the triangle is 75 cm. What will be the length of the third side ?

$\huge{\boxed{\rm{\red{Answer}}}}$

$\large{\boxed{\sf{Given \: that}}}$

• 1st side of triangle = 25 cm
• 2nd side of triangle = 21 cm
• Perimeter of triangle = 75 cm

$\large{\boxed{\sf{To \: find}}}$

• 3rd side of triangle.

$\large{\boxed{\sf{Solution}}}$

• 3rd side of triangle = 29 cm

$\large{\boxed{\sf{Full \: solution}}}$

• Perimeter of ∆ = 75 cm.

• Both sides of ∆ = 25 cm and 21 cm.

• We know that the 3rd sides is not given . Hence, let 3rd side of ∆ will be x.

$\large\purple{\texttt{Let's carry on}}$

$\large\purple{\texttt{According to the question}}$

$\large\pink{\texttt{P of ∆ = Sum of all sides}}$

$\implies$ 75 = 21 + 25 + x

$\implies$ 75 = 46 + x

$\implies$ 75 - 46 = x

$\implies$ 29 = x

$\implies$ x = 29 cm

$\implies$ Hence, 3rd side of ∆ is 29 cm.

$\large{\boxed{\boxed{\sf{Answer \: is \: 29 \: cm}}}}$

$\huge{\boxed{\rm{\red{R \: u \: confused \: ? \: \: \: \: Yes !}}}}$

$\huge{\boxed{\rm{\red{Don't \: worry \: !}}}}$

$\huge{\boxed{\rm{\red{Let's \: verified \: it \: :]}}}}$

$\large\underbrace\mathfrak\green{Verification \: is \: given \: below}$

$\implies$ 75 = 21 + 25 + x

$\implies$ 75 = 21 + 25 + 29

$\implies$ 75 = 46 + 29

$\implies$ 75 = 75

$\implies$ LHS = RHS

$\large{\boxed{\boxed{\sf{Hence \: it's \: verified}}}}$

$\huge{\boxed{\rm{\red{Know \: more}}}}$

$\large\underbrace\mathfrak\green{Define \: perimeter}$

A perimeter is a path that encompasses/surrounds a two-dimensional shape.

$\large\underbrace\mathfrak\green{Define \: triangle}$

A plane figure with three straight sides and three angles is known to be triangle.

$\large\underbrace\mathfrak\green{Triangle's \: symbol}$

The symbol of triangle is ∆.

$\large\underbrace\mathfrak\green{We \: also \: write}$

★ Perimeter as P

★ Triangle as ∆

@Itzbeautyqueen23

Hope it's helpful !

Thank you :)