The angles of a quadrilateral are in A.P. whose common difference is 10°. Find the numbers.
Here, we are given that the angles of a quadrilateral are in A.P, such that the common difference is 10°.
So, let us take the angles as $a-d, a, a+d, a+2 d$
Now, we know that the sum of all angles of a quadrilateral is 360°. So, we get,
$(a-d)+(a)+(a+d)+(a+2 d)=360$
$a-d+a+a+d+a+2 d=360$
$4 a+2(10)=360$
$4 a=360-20$
On further simplifying for a, we get,
$a=\frac{340}{4}$
$a=85$
So, the first angle is given by,
$a-d=85-10$
$=75^{\prime}$
Second angle is given by,
Third angle is given by,
$a+d=85+10$
$=95^{\circ}$
Fourth angle is given by,
$a+2 d=85+(2)(10)$
$=85+20$
$=105$
Therefore, the four angles of the quadrilateral are $75^{\circ}, 85^{\circ}, 95^{\circ}, 105^{\circ}$.