Question icon
Grade 1010 grade maths

In a triangle ABC , D and E are two points on side AB and AC . DC and AB meet at O . If angle OCE is 20 degree , angle OEC is 30 degree , angle EOC is 130 degree , angle OBC is 70 degree , angle ODB is 40 degree then what is the measure of angle DEO.

Question image for In a triangle ABC , D and E are two points on side
Profile image of Aausman
10 Years agoGrade 10
Answers icon

1 Answer

Profile image of Vijay Mukati
10 Years ago
Using the angle sum property of triangle and veritically opposite angles, we can find the following angles, DOB= 150, DOE=BOC=50, OBD=10, BCO=60, B=80, C = 80, Assume DEO= x and EDO = y. Therefore, x+y = 130---eq(1). and ADE = 140-y and AED = 150-x. So angle A = x+y-110. Now Use A+B+C = 180 to form eq(2). Solve the two equation to find angle x. Thanks.