Understanding Triangles

What is the sum of the interior angles of a triangle?

• 360°

• 90°

• 180°

• 270°

If angle D is 100° and angle E is 33°, what is the measure of angle F in triangle DEF?

• 77°

• 57°

• 47°

• 67°

In a triangle with angles in the ratio 2:3:5, what is the measure of the smallest angle?

• 72°

• 54°

• 36°

• 18°

If the angles of a triangle are in the ratio 2:3:5, what is the measure of the largest angle?

• 54°

• 72°

• 90°

• 108°

How do you find the measure of an angle in a triangle if you know the other two angles?

• Add the two known angles and subtract from 180°

• Add 90° to the sum of the two known angles

• Multiply the two known angles

• Divide the sum of the two known angles by 2

If angle 4 is 135° and angle 1 is supplementary to it, what is the measure of angle 1?

• 75°

• 65°

• 55°

• 45°

What type of triangle has one angle greater than 90°?

• Equilateral triangle

• Right triangle

• Acute triangle

• Obtuse triangle

Which triangle has all sides of different lengths?

• Equilateral triangle

• Isosceles triangle

• Right triangle

• Scalene triangle

What is a triangle with two equal sides called?

• Scalene triangle

• Isosceles triangle

• Right triangle

• Equilateral triangle

Which triangle has all angles less than 90°?

• Right triangle

• Acute triangle

• Obtuse triangle

• Scalene triangle