Question

Please say this answer ​

Answer 1

Solution :

iii)

Theorem : Angle opposite in an isosceles triangle are equal.

$\\ \large \sf \: so.. \\ \\ \large \tt \mapsto \: x = 50 \degree$

vi)

Applying the same Theorem :

• Given angle = x

$\\ \large \tt \implies \: x = x$

Two angles = x (each)

$\\ \large \underline{ \underline{ \sf \star \: \: angle \: \: sum \: \: property : }}$

Sum of three angles of a triangle = 180°

$\\ \large \implies \tt \: x + x + 40 \degree = 180 \degree \\ \\ \large \tt \implies \: 2x = 180 \degree - 40 \degree \\ \\ \large \tt \implies \: x = \frac{140 \degree}{2} \\ \\ \large \sf \therefore \: \: x = 70 \degree$

Check :

• value of x = 70°

$\\ \large \rm \implies \: 70 \degree+ 70 \degree + 40 \degree = 180 \degree \\ \\ \large \sf \leadsto \: \: 180 \degree = 180 \degree$

L.H.S = R.H.S

Hence Proved

ix)

Given Exterior angle = 30°

• take angle opposite to 30° = y

$\\ \large \rm \mapsto \: y = 30 \degree$

(Vertically Opposite Angles)

Applying Theorem:

x = y = 30°

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$\\ \large \underline{ \underline{ \sf \star \: \: answers: }}$

• x = 50°

• x = 70°

• x = 30°