Saved Bookmarks
| 1. |
In Fig. 10.39, A, B, C and D are four points on a circle. AC and BD intersect at a point E such that `/_B E C = 130o` and `/_E C D = 20odot` Find `/_B A Cdot` |
|
Answer» Please refer to video for the figure. Here, `/_BEC = 130^@ and /_ECD = 20^@``/_AEB+/_BEC = 180^@`(Sum of angles formed by a straight line is 180^@) `/_AEB = 180-130 =50^@` Also, `/_ABD = /_ACD` as these angles are subtended by a same chord on the circle. So,` /_ABD = /_ABE = 20^@` Now, in `Delta AEB` `/_ABE+/_AEB+/_EAB = 180^@` `EAB+50+20 = 180` `EAB= 110^@` So, `/_BAC = EAB = 110^@` |
|