## 1. Which of the following cannot represent the sides of a triangle?

### Answer:

### Explanation:

The sum of the lengths of any two sides of a triangle must be greater than the third side. 3 + 4 = 7 which is not greater than the third side.

## 2. In an equilateral triangle, each angle measures:

### Answer:

### Explanation:

An equilateral triangle has all three sides equal, and all its angles measure 60°.

## 3. The triangle with one angle measuring more than 90° is called:

### Answer:

### Explanation:

A triangle with one angle greater than 90° but less than 180° is termed as an obtuse-angled triangle.

## 4. The Pythagoras theorem is applicable to:

### Answer:

### Explanation:

Pythagoras theorem (a^2 + b^2 = c^2) is valid for a right-angled triangle where 'c' is the hypotenuse.

## 5. If the sides of a triangle are 15 cm, 15 cm, and 15 cm, then the triangle is:

### Answer:

### Explanation:

An equilateral triangle has all its sides of the same length.

## 6. If two angles of one triangle are equal to two angles of another triangle, then both triangles are:

### Answer:

### Explanation:

Triangles with corresponding angles equal are similar.

## 7. If the sides of a triangle are in the ratio 3:4:5, the triangle is:

### Answer:

### Explanation:

A triangle with sides in the ratio 3:4:5 is a Pythagorean triplet and represents a right-angled triangle.

## 8. In a triangle ABC, if AB = AC, then:

### Answer:

### Explanation:

In an isosceles triangle, angles opposite to equal sides are equal.

## 9. The sum of all the angles of a triangle is:

### Answer:

### Explanation:

The sum of all interior angles of a triangle is always 180°.

## 10. A triangle with all its angles less than 90° is called:

### Answer:

### Explanation:

An acute-angled triangle has all its angles less than 90°.

## 11. The perimeter of a triangle is:

### Answer:

### Explanation:

The perimeter of any polygon, including a triangle, is the sum of its sides.

## 12. In a right-angled triangle, the side opposite the right angle is called:

### Answer:

### Explanation:

The side opposite the right angle in a right-angled triangle is the longest side and is called the hypotenuse.

## 13. If two sides of a triangle are equal, then it is called:

### Answer:

### Explanation:

An isosceles triangle has two sides of equal length.

## 14. Which of the following can be the sides of a right-angled triangle?

### Answer:

### Explanation:

Using Pythagoras theorem, only the set of sides 6 cm, 8 cm, and 10 cm satisfy the condition a^2 + b^2 = c^2.

## 15. An exterior angle of a triangle is equal to:

### Answer:

### Explanation:

The measure of an exterior angle of a triangle is equal to the sum of the measures of the two non-adjacent interior angles.

## 16. If a triangle has sides of lengths 4 cm, 5 cm, and 7 cm, it is:

### Answer:

### Explanation:

A scalene triangle has all sides of different lengths.

## 17. The area of a triangle with base 'b' and height 'h' is:

### Answer:

### Explanation:

The area of a triangle is given by (base x height)/2.

## 18. The triangle with sides 5 cm, 12 cm, and 13 cm is:

### Answer:

### Explanation:

The sides 5 cm, 12 cm, and 13 cm form a Pythagorean triplet, which is characteristic of a right-angled triangle.

## 19. Which of the following is not a property of an equilateral triangle?

### Answer:

### Explanation:

An equilateral triangle has all its angles measuring 60°.

## 20. The triangle which has no equal sides and no equal angles is:

### Answer:

### Explanation:

A scalene triangle has all its sides and angles of different measures.