Question

Two angles of the quadrilateral are 30 and 40 and the remaining two angles are equal. Find the measure of all the angles of the quadrilateral.​

Answer 1

• 30°, 40°, 145° and 145°

Explanation:

We have, Two angles of the quadrilateral are 30 and 40.

• First angle will be 30° and the Second angle will 40°

• the remaining two angles are equal. Let us consider the remaining two angles be ,

• Third angle = x
• Fourth angle = x

As we know that sum of all the angles of the quadrilateral is 360°

1st angle + 2nd angle + 3rd angle + 4th angle = 360

`30 + 40 + x + x = 360`

combining like terms,

`70 + 2x = 360`

subtract 70 from both sides,

`2x = 360 -70`

`2x = 290`

Divide both sides by 2

`x = 145`

• Since the remaining two angles are equal. Hence, the measure of the third and fourth angle be 145°.

• Therefore the the measure of all the angles of the quadrilateral is 30°, 40°, 145° and 145°