Question

In ∆ABC,A=70°and AB=AC. find the value of B and C

Answer 1

Answer:

∠B = ∠C

∠B = 55°

∠C = 55°

Step-by-step explanation:

Given Problem:

In ∆ABC,A=70°and AB=AC. find the value of B and C.

Solution:

To Find:

Value of B and C.

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Method:

Given that,

In ∆ABC , AB = AC

So,

∠B, ∠C          (Angle opp to these sides are equal.)

We know that,

Sum property of Δ

So,

∠A + ∠B + ∠C = 180°

=>70°+2∠B = 180°              (∴∠B and ∠C)

=>2∠B = 180° - 70°

=> 2∠B = 110°

=> ∠B = $\dfrac{110}{2}$

=> ∠B = 55°

Hence,

Both ∠B and ∠C = 55°

Note:

Refer the Attachment for the figure.

Answer 2

Answer :-

• ∠A = 70°
• ∠B = 55°
• ∠C = 55°

Step-by-step explanation :-

Given :-

• ∠A = 70°

• AB = AC ----------1

To Find :-

• ∠B

• ∠C

Solution :-

in ΔABC

AB = AC ( Given )

∠B = ∠C ( Angles opposite to equal sides are equal ) --2

Now,

∠A + ∠B + ∠C = 180° ( Angle sum property )

∠A + 2∠B = 180° ( From 2 )

70 + 2∠B = 180°

2∠B = 180 - 70

2∠B = 110

∠B = 55°

Therefore ∠C = 55°