Triangle Angle Relationships

This video tutorial explains how to find angles in circles, focusing on tangents, semicircles, and isosceles triangles. It covers key concepts such as right angles formed by tangents and radii, and properties of triangles within semicircles. The video includes several examples and practice problems to reinforce learning.

What is the angle formed when a tangent meets a circle's radius?

• 120°

• 90°

• 60°

• 45°

What type of triangle is always formed within a semicircle?

• Right-angled

• Scalene

• Equilateral

• Isosceles

In an isosceles triangle within a circle, what can be said about the angles?

• All angles are equal

• Angles are complementary

• Two angles are equal

• All angles are different

If a diameter meets a tangent, what is the angle formed?

• 45°

• 120°

• 90°

• 60°

In a triangle with angles 39° and 51°, what is the third angle?

• 90°

• 70°

• 100°

• 80°

What is the angle opposite the hypotenuse in a right-angled triangle within a semicircle?

• 120°

• 60°

• 45°

• 90°

In a triangle with angles 30° and 30°, what is the third angle?

• 120°

• 90°

• 60°

• 150°

What is the sum of angles in any triangle?

• 90°

• 360°

• 180°

• 270°

If two angles in a triangle are 70° and 90°, what is the third angle?

• 20°

• 30°

• 40°

• 50°

What is the angle formed when a tangent meets a radius?

• 45°

• 90°

• 60°

• 120°