Question

there are three angles of quadrilateral 60 80and 120 find the fourth angled​

Answer 1

Answer:

100

Step-by-step explanation:

As we know that sum of all angles of angles in a quadrilateral is 360

GIVEN:

3 angles of quadrilateral

60

80 and

120

TO FIND:

4th unknown angle of quadrilateral

SOLVING:

let the unknown angle be x

sum of all four angles = 360

60 + 80 + 120 + x =360

260 + x = 360

x = 360 - 260

x = 100

PROPERTY USED:

Interior angle sum property of quadrilateral

FORMULA USED:

sum of all angles = 360

60 + 80 + 120 + x = 360

ANSWER:

x = 100

Answer 2

$\huge{\red {\mathfrak {Question:-}}}$

• There are the three angles of quadrilateral 60°,80°and 120°. Find the fourth angle.

$\huge{\pink {\mathfrak {Solution:-}}}$

$\underline {\bold{Given:}}$

• First angle =60 °
• Second angle =80°
• Third angle=120°

$\underline {\bold{To\:Find:}}$

• The fourth angle.

We know that sum of all angles of quadrilateral is 360°.

Let the fourth angle be x°.

Atq,

$\implies 60^{\circ} + 80^{ \circ} + 120^{\circ} + x^{ \circ} = 360^{\circ} \\ \\ \implies 260^{\circ} + x^{ \circ} = 360^{\circ} \\ \\\implies x^{\circ} = 360^{ \circ} - 260^{\circ} \\ \\ \implies x^{\circ} = 100^{ \circ}$

$\green {\therefore{\tt{The\:fourth\: angle\: is\:100^{\circ}.}}}$

$\rule {207}{1}$

$\underline {\bold{Verification:-}}$

We know that sum of all angles of quadrilateral is 360°.

$\implies First \: angle + Second \: angle +\:Third \:angle + Fourth \: angle =360^{\circ}\\ \\ \implies 60^{\circ} + 80^{ \circ} + 120^{\circ} + 100^{ \circ} = 360^{\circ} \\ \\ \implies 360^{\circ} = 360^{\circ} \\ \\ \implies LHS= RHS$

$\rule {207}{2}$