Advertisements
Advertisements
Question
In ΔABC, if ∠A = 40° and ∠B = 60°. Determine the longest and shortest sides of the triangle.
Advertisements
Solution
Given that in , ΔABC ∠A =40° and ∠B=60° We have to find longest and shortest side We know that,
Sum of angles in a triangle180°
⇒∠A+∠B+∠C=180°
⇒40°+60°+∠C=180°
⇒∠C=180° -(40° +60° )
=180° -100° =80°
∴∠C = 80°
Now,
⇒ 40<60<80⇒∠A< ∠B < ∠C
⇒ ∠Cis greater angle and ∠A is smaller angle
Now, ∠A<∠B<∠C
⇒ BC<AAC<AB
[∵Side opposite to greater angle is larger and side opposite to smaller angle is smaller]
∴ AB is longest and BC is smallest or shortest side.
APPEARS IN
RELATED QUESTIONS
In an isosceles triangle ABC, with AB = AC, the bisectors of ∠B and ∠C intersect each other at O. Join A to O. Show that:
- OB = OC
- AO bisects ∠A
ABC is a triangle in which altitudes BE and CF to sides AC and AB are equal (see the given figure). Show that
- ΔABE ≅ ΔACF
- AB = AC, i.e., ABC is an isosceles triangle.

ABC and DBC are two isosceles triangles on the same base BC (see the given figure). Show that ∠ABD = ∠ACD.

Determine the measure of each of the equal angles of a right-angled isosceles triangle.
Prove that the medians of an equilateral triangle are equal.
Find the measure of each exterior angle of an equilateral triangle.
If the bisector of the exterior vertical angle of a triangle be parallel to the base. Show that the triangle is isosceles.
Prove that each angle of an equilateral triangle is 60°.
Which of the following statements are true (T) and which are false (F):
The measure of each angle of an equilateral triangle is 60°
Fill the blank in the following so that the following statement is true.
Sides opposite to equal angles of a triangle are ......
If the angles A, B and C of ΔABC satisfy the relation B − A = C − B, then find the measure of ∠B.
In a triangle ABC, if AB = AC and AB is produced to D such that BD = BC, find ∠ACD: ∠ADC.
Line segments AB and CD intersect at O such that AC || DB. If ∠CAB = 45° and ∠CDB = 55°, then ∠BOD =
The base BC of triangle ABC is produced both ways and the measure of exterior angles formed are 94° and 126°. Then, ∠BAC =
If the bisectors of the acute angles of a right triangle meet at O, then the angle at Obetween the two bisectors is
The angles of a right angled triangle are
D is a point on the side BC of a ∆ABC such that AD bisects ∠BAC. Then ______.
M is a point on side BC of a triangle ABC such that AM is the bisector of ∠BAC. Is it true to say that perimeter of the triangle is greater than 2 AM? Give reason for your answer.
Find all the angles of an equilateral triangle.
Show that in a quadrilateral ABCD, AB + BC + CD + DA > AC + BD
