Practice Set 8.2
(1) In the figure below, sides of equal length are shown by the same marking.
Write the type of triangle based on it:
(i)
△DEF is an equilateral triangle.
(ii)
△MAN is an isosceles triangle.
(iii)
△EFG is a scalene triangle.
Solution
(i)
△DEF is an equilateral triangle.
(ii)
△MAN is an isosceles triangle.
(iii)
△EFG is a scalene triangle.
(2) Write the type of triangle from the information given below:
(i)
In △ABC, m∠A = 63°, m∠B = 52°, m∠C = 65°
(ii)
In △RST, seg RS and seg ST are of equal length.
(iii)
In △LMN, ∠LMN is a right angle.
(iv)
In △SDO, m∠OSD = 135°.
(v)
All the sides of △RTM are equal.
(vi)
The sides of △DEF are 5.3 cm, 4.2 cm and 6.6 cm respectively.
Solution
Ans (i)
In △ABC, m∠A = 63°, m∠B = 52°, m∠C = 65° all are acute angles.
∴ △ABC is an acute angled triangle.
Ans (ii)
In △RST, seg RS and seg ST are of equal length.
∴ △RST is an isosceles triangle.
Ans (iii)
In △LMN, ∠LMN is right angle.
∴ △LMN is a right angled triangle.
Ans (iv)
In △SDO, m∠OSD = 135°.
∴ △SDO is an obtuse angled triangle.
Ans (v)
All the sides of △RTM are equal.
∴ △RTM is an equilateral triangle.
Ans (vi)
The sides of △DEF are 5.3 cm, 4.2 cm and 6.6 cm respectively.
∴ △DEF is a scalene triangle.