Q. 494.0( 3 Votes )

# The angles of a triangle are in the ratio 3:5:7. The triangle is

A. acute angled

B. right – angled

C. obtuse angled

D. isosceles

Answer :

Let x be the common multiple.

3x + 5x + 7x = 180

15x = 180

x = 180/15

x = 12

3x = 3 X 12 = 36

5x = 5 X 12 = 60

7x = 7 X 12 = 84

Since, all the angles are less than 90^{o}. So, it is acute angled triangle.

Rate this question :

Prove that the angles opposite to equal sides of a triangle are equal

RS Aggarwal & V Aggarwal - MathematicsIf the sides of a triangle are produced in order, then the sum of the three exterior angles so formed is

RD Sharma - MathematicsIn Δ *ABC*, if ∠*A* = 100° *AD* bisects ∠*A* and AD⊥BC. Then, ∠*B* =

D is any point on side AC of a ΔABC with AB = AC. Show that CD < BD.

NCERT Mathematics ExemplarIn a triangle *ABC*, if *AB* = *AC* and AB is produced to *D* such that *BD* = *BC*, find ∠*ACD*: ∠*ADC.*

If the side of a triangle are produced in order, Prove that the sum of the exterior angles so formed is equal to four right angles.

RS Aggarwal & V Aggarwal - Mathematics

In Δ *ABC*, ∠*A*=50° and *BC* is produced to a point *D*. If the bisectors of ∠*ABC* and ∠*ACD* meet at *E*, then ∠*E* =

Compute the value of *x* in each of the following figures:

(i)

(ii)

(iii)

(iv)

RD Sharma - Mathematics

In Δ *PQR*, if *PQ*=*QR* and *L, M* and *N* are the mid-point of the sides *PQ, QR* and *RP* respectively. Prove that *LN*=*MN*.

In a right-angled triangle, one of the acute measures 53°^{.} Find the measure of each angle of the triangle.