Triangle

In an equilateral triangle, all angles are:

• Congruent angles

• Obtuse angles

• Acute angles

• Right angles

Answer explanation

The sum of all three angles in any triangle is 180 degrees. So each angle in an equilateral triangle is of 60 degrees.

A triangle with one angle greater than 90⁰ is called:

• Obtuse triangle

• Acute triangle

• Isosceles triangle

• Equilateral triangle

Answer explanation

Triangle is a triangle in which one of the interior angles measures more than 90° degrees.

Which of the following triangles has two

sides of equal length?

• Right triangle

• Equilateral triangle

• Isosceles triangle

• Scalene triangle

Answer explanation

Triangle with two equal sides. An isosceles triangle, therefore, has both two equal sides and two equal angles.

The sum of the angles in any triangle is equal to:

• 360 degrees

• 120 degrees

• 180 degrees

• 90 degrees

Answer explanation

One exterior angle is equal to the sum of the other two angles in the triangle.

A triangle with all sides of different lengths is called:

• Scalene triangle

• Isosceles triangle

• Equilateral triangle

• Right triangle

Answer explanation

In figure, the length of the sides of the ∆ABC are all different. Hence, such triangle is called scalene triangle

In a right-angled triangle, the side

opposite the right angle is called the:

• Adjacent side

• Perpendicular

• Base

• Hypotenuse

Answer explanation

The hypotenuse of a right triangle is always the side opposite the right angle. It is the longest side in a right triangle.

Two angles of a triangle measure 30 degrees and 60 degrees. What is the measure of the third angle?

• 120 degrees

• 90 degrees

• 60 degrees

• 30 degrees

Answer explanation

According to the angle sum property of the triangles, the sum of all three angles should be equal to 180°.

The third angle = 180° - (30° + 60°)

= 90°

The longest side of a triangle is called the:

• Perimeter

• Hypotenuse

• Altitude

• Base

Answer explanation

The longest side of the right triangle (the side opposite the 90⁰ angle) is called the hypotenuse and the other two (shorter) sides are called the legs of the triangle.

If two angles of a triangle are 45 degrees each, what is the measure of the third angle?

• 90 degrees

• 45 degrees

• 75 degrees

• 60 degrees

Answer explanation

Measure of two angles of a triangle are 45° and 45°

Sum of all three angles of triangle = 180°

Therefore, measure of the third angle = 180° - (45° + 45°) = 90°

If a triangle has sides measuring 8 cm, 10 cm, and 12 cm, what type of triangle is it?

• Equilateral triangle

• Isosceles triangle

• Scalene triangle

• Right triangle

Answer explanation

Triangle in which all three sides are in different lengths, and all three angles are of different measures.

So All three angles are of different Measures.