In the worksheet on triangle we will solve 12 different types of questions.

**1.** Take three non - collinear points L, M, N. Join LM, MN and NL. What figure do you get?

Name:

(a) The side opposite to ∠L. ..................................

(b) The angle opposite to side LN. ..................................

(c) The vertex opposite to side MN. ..................................

(d) The side opposite to angle N. ..................................

**2. Find the number of triangles in the figure given below:**

**Answer:**

There are 8 triangles (∆HAD; ∆BEF; ∆BHI; ∆AIJ; ∆CFH; ∆FGD; ∆GEJ; ∆ GAC)

**3. Write the name of the vertices, sides and angle of the
given triangle. Also give the name of the triangle in 3 different ways.**

**4. Classify the triangle into acute triangle, obtuse triangle and right triangle with the following angles:**

(a) 90°, 45°, 45°

(b) 60°, 60°, 60°

(c) 80°, 60°, 40°

(d) 130°, 40°, 10°

(e) 90°, 35°, 55°

(f) 92°, 38°, 50°

**5. Identify the type of triangle based on the lengths of
the sides.**

**Answer:**

(i) Isosceles Triangle

**
**

(ii) Equilateral Triangle

(iii) Scalene Triangle

**6. Classify the triangle according to sides, that is, equilateral, isosceles and scalene triangles**

(a) 6 cm, 3 cm, 5 cm.

(b) 6 cm, 6 cm, 6 cm.

(c) 7 cm, 7 cm, 5 cm.

(d) 8 cm, 12 cm, 10 cm.

(e) 3 cm, 4 cm, 5 cm.

(f) 3.5 cm, 3.5 cm, 4.5 cm.

**7. Is it possible to have a triangle with the following angles and sides? Give reason in support of your answer.**

(a) 110°, 60°, 30°

(b) 70°, 70°, 70°

(c) 80°, 35°, 65°

(d) 7 cm, 3 cm, 4 cm.

(e) 50°, 50°, 90°

(f) 10 cm, 12 cm, 2 cm.

**8. Find the perimeter of a triangle when its sides are:**

(a) AB = 7.6 cm, BC = 4.5 cm, CA = 6.3 cm.

(b) PQ = 4.00, QR = 3 cm, RP = 5 cm.

(c) LM = 4.5 cm, MN = 3.6 cm, NL = 6.2 cm.

**9. If in a triangle LMN:**

(a) ∠L = 80°, ∠M = 50°, find ∠N,

(b) ∠M = 60°, ∠N = 60°, find ∠L,

(c) ∠M = 100°, ∠ N = 30°, find ∠ L,

(d) ∠N = 90°, ∠L = 45°, find ∠M.

Mention the kind of triangle also.

**10.** Draw any triangle and name it PQR. Measure its sides and
classify the triangle as Isosceles triangle, scalene triangle or equilateral
triangle.

**11.** The angle of a triangle is in the ratio of 2: 3: 4. Find the measure of each angle of the triangle.

**12.** One of the two equal angles of an isosceles triangle measures 55°. Determine the other angles.

**13.** The perimeter of a triangle is 24 cm. Two of its sides are 8 cm and 9 cm. Find the length of its third side.

**14.** Each side of a ∆ is one third of its perimeter. What kind of triangle is this?

**15.** One of the acute angles of a right triangle is 48°. Find the other acute angle.

**16.** Say whether the following statements are true or false:

(a) All the angles of an isosceles triangle are equal.

(b) If one angle of a triangle is obtuse, the other two angles must be acute.

(c) A right triangle can be equilateral.

(d) Equiangular triangle has its three sides also equal.

(e) A triangle can have two obtuse angles.

**17. Fill in the blanks:**

(i) A triangle is ……………………… sided polygon.

(ii) A triangle has ……………………… vertices and ……………………… sides.

(iii) A triangle can be classified on the basis of ……………………… and ……………………….

(iv) A triangle with all sides equal is called a ……………………… triangle.

(v) A triangle whose 2 sides are equal is called a ……………………… triangle.

(vi) A triangle with unequal sides is called a ……………………… triangle.

**Answer:**

(i) three

(ii) three, three

(iii) sides, angles

(iv) equilateral

(v) isosceles

(vi) scalene

**Examples of Properties of Triangle**

**To Construct a Triangle whose Three Sides are given.**

**To Construct a Triangle when Two of its Sides and the
included Angles are given.**

**To Construct a Triangle when Two of its Angles and the included
Side are given.**

**To Construct a Right Triangle when its Hypotenuse and One Side
are given.**

**Worksheet on Construction of Triangles.**

**5th Grade Geometry Page**

**5th Grade Math Problems**

**5th Grade Math Worksheets**

**From Worksheet on Triangle to HOME PAGE**

**Didn't find what you were looking for? Or want to know more information
about Math Only Math.
Use this Google Search to find what you need.**

## New! Comments

Have your say about what you just read! Leave me a comment in the box below. Ask a Question or Answer a Question.