Advertisements
Advertisements
Question
The angle of a vertex of an isosceles triangle is 100°. Find its base angles.
Advertisements
Solution
In Δ ABC,

∵ AB = AC.
∴ ∠B = ∠C
But ∠A = 100°
and ∠A + ∠B + ∠C = 180° ..........(Angles of a triangle)
⇒ 100° + ∠B + ∠B = 180°
⇒ 2 ∠B = 180°− 100°
⇒ 2 ∠B = 80°
∴ ∠B =`(80°)/2=40°`
Hence ∠B = ∠C = 40°
APPEARS IN
RELATED QUESTIONS
If the angles of a triangle are in the ratio 1: 2 : 3, determine three angles.
In the given figure, AC ⊥ CE and ∠A : ∠B : ∠C = 3 : 2 : 1, find the value of ∠ECD.

Is the following statement true and false :
An exterior angle of a triangle is equal to the sum of the two interior opposite angles.
The sum of two angles of a triangle is equal to its third angle. Determine the measure of the third angle.
In ΔRST (See figure), what is the value of x?

Find the unknown marked angles in the given figure:

One angle of a triangle is 61° and the other two angles are in the ratio `1 1/2: 1 1/3`. Find these angles.
Find x, if the angles of a triangle is:
2x°, 4x°, 6x°
The length of the three segments is given for constructing a triangle. Say whether a triangle with these sides can be drawn. Give the reason for your answer.
7 cm, 24 cm, 25 cm
Can we have two acute angles whose sum is an obtuse angle? Why or why not?
