Study the given figure and identify the following triangles.(a) equila

1.	Study the given figure and identify the following triangles.(a) equilateral triangle(b) isosceles triangles(c) scalene triangles(d) acute triangles(e) obtuse triangles(f) right triangles
Answer» (a) BC = 1 + 1 + 1 + 1 = 4 cm AB = AC = 4 cm ∆ABC is an equilateral triangle. (b) ∆ABC and ∆AEF are isosceles triangles. Since AB = AC = 4 cm Also AE = AF. (c) In a scalene triangle, no two sides are equal. ∆AEB, ∆AED, ∆ADF, ∆AFC, ∆ABD, ∆ADC, ∆ABF and ∆AEC are scalene triangles. (d) In an acute-angled triangle all the three angles are less than 90°. ∆ABC, ∆AEF, ∆ABF and ∆AEC are acute-angled triangles. (e) In an obtuse-angled triangle any one of the angles is greater than 90°. ∆AEB and ∆AFC are obtuse angled triangles. (f) In a right triangle, one of the angles is 90°. ∆ADB, ∆ADC, ∆ADE and ∆ADF are right-angled triangles.

Study the given figure and identify the following triangles.(a) equilateral triangle(b) isosceles triangles(c) scalene triangles(d) acute triangles(e) obtuse triangles(f) right triangles

Answer»

(a) BC = 1 + 1 + 1 + 1 = 4 cm

AB = AC = 4 cm

∆ABC is an equilateral triangle.

(b) ∆ABC and ∆AEF are isosceles triangles.

Since AB = AC = 4 cm Also AE = AF.

(c) In a scalene triangle, no two sides are equal.

∆AEB, ∆AED, ∆ADF, ∆AFC, ∆ABD, ∆ADC, ∆ABF and ∆AEC are scalene triangles.

(d) In an acute-angled triangle all the three angles are less than 90°.

∆ABC, ∆AEF, ∆ABF and ∆AEC are acute-angled triangles.

(e) In an obtuse-angled triangle any one of the angles is greater than 90°.

∆AEB and ∆AFC are obtuse angled triangles.

(f) In a right triangle, one of the angles is 90°.

∆ADB, ∆ADC, ∆ADE and ∆ADF are right-angled triangles.