Q. 19

# Math the following columns:

The correct answer is:

(a)-……, (b)-……, (c)-……., (d)-……

Answer :

a) In ∆ABC, ∠ A=70°

As AB = AC and we know that angles opposite to equal sides are equal

∴ In triangle ABC,

∠ A + ∠ B + ∠ C = 180^{o}

70^{o} + 2∠ C = 180^{o}

2∠ C = 180^{o} – 70^{o}

∠ C =

∴ ∠ C = 55^{o}

(b) We know that,

Angles opposite to equal sides are equal

It is given that, vertical angle of the isosceles triangle = 120^{o}

Let the base angle be x

∴ 120° + x + x = 180°

120° + 2x = 180°

2x = 180° – 120°

2x = 60°

x =

x = 30°

Hence, each base angle of the isosceles triangle is equal to 30^{o}

(c) We know that,

The sum of the three medians of the triangle is always less than the perimeter

(d) We know that,

In a triangle the sum of any two sides is always greater than the third side

Hence, the correct match is as follows:

(a) – (s)

(b) – (r)

(c) – (p)

(d) – (q)

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