Find the sum of ∠1+∠2+∠3+∠4+∠5+∠6+∠7+∠8+∠9
Since, sum of all angles of triangle is 180°
We have,
In △ABC
⇒∠1+∠2+∠3=180°
And in △ACD
⇒∠4+∠5+∠6=180°
And in △AED
⇒∠7+∠8+∠9=180°
∴∠1+∠2+∠3+∠4+∠5+∠6+∠7+∠8+∠9=3✖180°=540°
Hence, the sum of ∠1+∠2+∠3+∠4+∠5+∠6+∠7+∠8+∠9=540°.
In the given figure, l∥m and t is transversal. If ∠1 and ∠2 are in the ratio 5:7, find the measure of each of the angles∠1,∠2,∠3 and ∠8.
Question 39
In the given figure (Q .No. 37) which of the following is true? (a) ∠1=∠5 (b) ∠4=∠8 (c) ∠5=∠8 (d) ∠3=∠7