Advertisements
Advertisements
Question
Find all the three angles of the ΔABC
Advertisements
Solution
∠A + ∠B = ∠ACD ...(An exterior angle of a triangle is sum of its interior opposite angles)
x + 35 + 2x – 5 = 4x – 15
3x + 30 = 4x – 15
30 + 15 = 4x – 3x
45° = x
∠A = x + 35°
= 45° + 35°
= 80°
∠B = 2x – 5
= 2(45°) – 5°
= 90° – 5°
= 85°
∠ACD = 4x – 15
= 4(45°) – 15°
= 180° – 15°
= 165°
∠ACB = 180° – ∠ACD
= 180° – 165°
= 15°
∠A = 80°, ∠B = 85° and ∠C = 15°.
APPEARS IN
RELATED QUESTIONS
Can a triangle have All angles equal to 60°? Justify your answer in case.
If the bisector of the exterior vertical angle of a triangle be parallel to the base. Show that the triangle is isosce
Is the following statement true and false :
A triangle can have two right angles.
Is the following statement true and false :
A triangle can have at most one obtuse angles.
In the given figure, AB divides ∠DAC in the ratio 1 : 3 and AB = DB. Determine the value of x.
In Δ ABC, if u∠B = 60°, ∠C = 80° and the bisectors of angles ∠ABC and ∠ACB meet at a point O, then find the measure of ∠BOC.
State, if the triangle is possible with the following angles :
125°, 40°, and 15°
If the angles of a triangle are equal, find its angles.
The angle of a vertex of an isosceles triangle is 100°. Find its base angles.
In ∆ABC, C = 56° C = 56° ∠B = ∠C and ∠A = 100° ; find ∠B.
