Selina solutions for Mathematics [English] Class 6 chapter 26 - Triangles (Including Types, Properties and Constructions) [Latest edition]

In the following, find the marked unknown angle:

In the following, find the marked unknown angle:

In the following, find the marked unknown angle:

Can a triangle together have the following angles?

55°, 55° and 80°

Can a triangle together have the following angles?

33°, 74° and 73°

Can a triangle together have the following angles?

85°, 95° and 22°

Find x, if the angles of a triangle is:

x°, x°, x°

Find x, if the angles of a triangle is:

x°, 2x°, 2x°

Find x, if the angles of a triangle is:

2x°, 4x°, 6x°

One angle of a right-angled triangle is 70°. Find the other acute angle.

In ∆ABC, ∠A = ∠B = 62° ; find ∠C.

In ∆ABC, C = 56° C = 56° ∠B = ∠C and ∠A = 100° ; find ∠B.

Find, giving a reason, the unknown marked angles, in a triangle drawn below:

Find, giving a reason, the unknown marked angles, in a triangle drawn below:

Find, giving a reason, the unknown marked angles, in a triangle drawn below:

Classify the following triangle according to angle:

Classify the following triangle according to angle:

Classify the following triangle according to angle:

Classify the following triangle according to sides:

Classify the following triangle according to sides:

Classify the following triangle according to sides:

Classify the following triangle according to sides:

Construct traingle ABC, when : AB = 6 cm, BC = 8 cm and AC = 4 cm.

Construct traingle ABC, when : AB = 3.5 cm, AC = 4.8 cm and BC = 5.2 cm.

Construct triangle ABC, when: AB = BC = 5 cm and AC = 3 cm. Measure angles A and C. Is ∠A = ∠C?

Construct traingle ABC, when : AB = BC = CA = 4.5 cm. Measure all the angles of the triangle. Are they equal?

Construct traingle ABC, when : AB = 3 cm, BC = 7 cm and ∠B = 90°.

Construct traingle ABC, when : AC = 4.5 cm, BC = 6 cm and ∠C = 60°.

Construct traingle ABC, when : AC = 6 cm, ∠A = 60“ and ∠C = 45°. Measure AB and BC.

Construct traingle ABC, when : AB = 5.4 cm, ∠A = 30° and ∠B = 90°. Measure ∠C and side BC.

Construct traingle ABC, when: AB = 7 cm, ∠B = 120° and ∠A = 30°. Measure AC and BC. 

Construct traingle ABC, when: BC = 3 cm, AC = 4 cm and AB = 5 cm. Measure angle ACB. Give a special name to this triangle.

If each of the two equal angles of an isosceles triangle is 68°, find the third angle.

One of the angles of a triangle is 110°, the two other angles are equal. Find their value.

The angles of a triangle are in the ratio 3:5: 7. Find each angle.

The angles of a triangle are (2x – 30°),(3x – 40°) and ( x + 10°) Find the value of x .

In the following figure, triangle ABC is equilateral and triangle PBC is isosceles. If PBA = 20°; find angle PBC.

In the following figure, triangle ABC is equilateral and triangle PBC is isosceles. If PBA = 20°; find angle BPC.

Construct a triangle ABC given AB = 6 cm, BC = 5 cm and CA = 5.6 cm. From vertex A draw a perpendicular on to side BC. Measure the length of this perpendicular.

Construct a triangle PQR, given PQ = 6 cm, ∠P = 60° and ∠Q = 30°. Measure angle R and the length of PR.

Construct a triangle ABC given BC = 5 cm, AC = 6 cm and ∠C = 75°. Draw the bisector of the interior angle at A. Let this bisector meet BC at P ; measure BP

Using ruler and a pair compass only, construct a triangle XYZ given YZ = 7 cm, ∠XYZ = 60° and ∠XZY = 45°. Draw the bisectors of angles X and Y.

Using ruler and a pair compass only, construct a triangle PQR, given PQ = 5.5 cm, QR = 7.5 cm and RP = 6 cm. Draw the bisectors of the interior angles at P, Q and R. Do these bisectors meet at the same point ?

One angle of a triangle is 80° and the other two are in the ratio 3 : 2. Find the unknown angles of the triangle

Find the value of x if ∠A = 32°, ∠B = 55° and obtuse angle AED = 115°.