Question

triangle ABC me AB=BC CONE B =x and cone A = (2x-20) degree toh cone B ki value
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Answer 1

Answer:

From fig.,

In △ABC,

∵AB=BC

∴∠C=∠A=(2x−20)°(∵ angle oppsite to the equal sides are equal)

∠B=x°

As we know that sum of all interior angles of a triangle is 180°.

∴∠A+∠B+∠C=180°

⇒(2x−20)°+x°+(2x−20)°=180°

⇒(5x−40)°=180°

⇒5x=180°+40°

⇒x=

5

220

=44°

∴∠B=44°

Hence, the correct answer is 44.

Answer 2

Answer:

Value of ∠B = 44°

Step-by-step explanation:

Given: In △ABC, AB = BC

∠B = x, ∠A = (2x - 20°)

We know that:

Isosceles triangle states that If two sides of a triangle are equal then angles opposite those sides are equal:

∠A = ∠C [∵ AB = BC]

∠A = ∠C = (2x - 20°)

We also know that:

Sum of all the three angles of a triangle is equal to 180:

According to question:

∠A + ∠B + ∠C = 180°

→ x + (2x - 20°) + (2x - 20°) = 180°

→ x + 2x + 2x - 20° - 20° = 180°

→ 5x - 40° = 180°

→ 5x = 180° + 40°

→ 5x = 220°

→ x = 44°

∴ ∠B = x = 44°