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
ABC is a triangle in which ∠A — 72°, the internal bisectors of angles B and C meet in O.
Find the magnitude of ∠BOC.
If the sides of a triangle are produced in order, then the sum of the three exterior angles so formed is
In a triangle PQR, ∠P = 60° and ∠Q = ∠R, find ∠R.
Calculate the unknown marked angles of the following figure :
Find, giving a reason, the unknown marked angles, in a triangle drawn below:
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
The exterior angle of a triangle is equal to the sum of two
In the following figure, ∠BAC = 90° and AD ⊥ BC. The number of right triangles in the figure is ______.
What is common in the following figure?
 |
 |
| (i) | (ii) |
Is figure (i) that of triangle? if not, why?
Jincy used these shapes to make drawings of fish.
Now you also use some shapes to draw the different sea animals shown below.
Sea urchin
Lobster
Eel
Red snapper
Octopus
Clam
Parrotfish
Prawn
Cuttlefish
Jellyfish
Squid
Silver pomfret
Crab
