Question

Answer all this. Please help me....

Answer 1

15. -8/15 + 4/5 = 4/5 + (-8/15)
-8/15 + 4/5 = 4/5 - 8/15
0.26 = 0.26
18. Let ABCD a quadrilateral . Join AC .
Clearly, Angle1+ Angle2 = A .......(i)
And, Angle3 + Angle4 = C ........(ii)
We know that the sum of the angles of the triangle is 180°
Therefore, from triangle ABC,we have
Angle2 + Angle4 + AngleB = 180°
From triangle ACD ,we have
Angle1 + Angle3 + AngleD = 180°
Adding the angle on either side , we get
Angle2 + Angle4 + AngleB + Angle1 + Angle3 + AngleD = 360°
(Angle1 + Angle2) + AngleB + (Angle3 + Angle4) + AngleD = 360°
AngleA + AngleB + AngleC + AngleD = 360° [using (i) and (ii)]
Hence, sum of four angles of a quadrilateral is 360°

Answer 2

Answer:

bold - \bold{text}

$\fbox{ don't know answer }$