
Given: \(∠\)AOC + \(∠\)BOE = 70° and \(∠\)BOD = 40°
To find: \(∠\) BOE, and Reflex \(∠\)COE

From Figure,
(\(∠\)AOC +\(∠\)BOE +\(∠\)COE) and (\(∠\)COE +\(∠\)BOD +\(∠\)BOE) forms a straight line.
So, \(∠\)AOC+\(∠\)BOE +\(∠\)COE = \(∠\)COE +\(∠\)BOD+\(∠\)BOE = 180°
Now, by putting the values of \(∠\)AOC + \(∠\)BOE = 70° and \(∠\)BOD = 40° we get
\(∠\)COE = 110° and \(∠\)BOE = 30°
So, reflex \(∠\)COE = 360o – 110o = 250o



| A | B |
|---|---|
| (i) broke out | (a) an attitude of kindness, a readiness to give freely |
| (ii) in accordance with | (b) was not able to tolerate |
| (iii) a helping hand | (c) began suddenly in a violent way |
| (iv) could not stomach | (d) assistance |
| (v) generosity of spirit | (e) persons with power to make decisions |
| (vi) figures of authority | (f) according to a particular rule, principle, or system |
ABC is a triangle in which altitudes BE and CF to sides AC and AB are equal (see Fig). Show that
(i) ∆ ABE ≅ ∆ ACF
(ii) AB = AC, i.e., ABC is an isosceles triangle.

Section | Number of girls per thousand boys |
|---|---|
Scheduled Caste (SC) | 940 |
Scheduled Tribe (ST) | 970 |
Non-SC/ST | 920 |
Backward districts | 950 |
Non-backward districts | 920 |
Rural | 930 |
Urban | 910 |
(i) Represent the information above by a bar graph.
(ii) In the classroom discuss what conclusions can be arrived at from the graph.