Question

The sum of the angles in a hexagon is 720°.

Answer 1

Given:

The sum of the angles in a hexagon is 720°.

$m\angle A=90^\circ,m\angle B=126.87^\circ,m\angle C=(3x)^\circ,m\angle D=90^\circ, m\angle E=143.13^\circ, m\angle F=143.13^\circ.$

To find:

(a) Equation to solve the value of x.

(b) The value of x.

(c) The measure of angle C.

Solution:

(a)

We have,

$m\angle A=90^\circ,m\angle B=126.87^\circ,m\angle C=(3x)^\circ,m\angle D=90^\circ, m\angle E=143.13^\circ, m\angle F=143.13^\circ.$

The sum of the angles in a hexagon is 720°.

$m\angle A+m\angle B+m\angle C+m\angle D+m\angle E+m\angle F =270^\circ$

$90^\circ+126.87^\circ+(3x)^\circ+90^\circ+143.13^\circ+143.13^\circ =270^\circ$

$90+126.87+(3x)+90+143.13+143.13 =720$

Therefore, the required equation is $90+126.87+(3x)+90+143.13+143.13 =720$.

(b)

On solving the above equation, we get

$593.13+3x =720$

$3x =720-593.13$

$3x =126.87$

Divide both sides by 3.

$x =\dfrac{126.87}{3}$

$x =42.29$

Therefore, the value of x is 42.29.

(c)

We need to find the measure of angle C.

$m\angle C=(3x)^\circ$

$m\angle C=(3\times 42.29)^\circ$

$m\angle C=126.87^\circ$

Therefore, the measure of angle C is 126.87 degrees.