every interior angle has measure 18*180/20 = 162°
So, any angle formed by three vertices will be a multiple of that.
The points A,B,C and D are consecutive vertices of a regular polygons with 20 sides.Calculate angles
(a) ABC
(b) ACD
(c) ABD
8 answers
but the answer of (a).162 (b).153 (c).153
gee. so which choice is a multiple of 162???!!!
come on ...
come on ...
I understand the 162,but how comes 153
Ah. I see what I did wrong.
Since ∆ABC is an isosceles ∆ with vertex angle of 162°, its two base angles (∡BAC and ∡BCA) are each 9°. So, ∡ACD = ∡ABD = 162-9 = 153°.
If you draw the diagram of vertices A,B,C,D this is clear.
Since ∆ABC is an isosceles ∆ with vertex angle of 162°, its two base angles (∡BAC and ∡BCA) are each 9°. So, ∡ACD = ∡ABD = 162-9 = 153°.
If you draw the diagram of vertices A,B,C,D this is clear.
I got It. Thanks.
(a) 162 (b) 153 (c) 153
(i)162 (ii) 153 (iii) 153
1 answer