Find the Missing Angle on an Isosceles Triangle
- Angles in a triangle add up to 180°
- Isosceles Triangle: 2 equal base angles
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💡 Quick Help Guide
- In this exercise, you are given one angle of an isosceles triangle and you need to find the missing angle x.
- ▶ Look carefully at the triangle and the congruency marks (ticks) on the sides.
- ▶ Remember that angles in a triangle always add up to 180°.
- ▶ If finding the vertex angle, use: x = 180° − (2 × base angle).
- ▶ If finding a base angle, use: x = (180° − vertex angle) ÷ 2.
- ▶ Calculate the value of x and enter your answer in the box.
- ▶ Click the check button to see if your answer is correct.
- Master the properties of isosceles triangles through practice!