Geometry: Isosceles Triangle Perimeter

This video tutorial covers a practice SAT math question from the geometry section, focusing on finding the perimeter of an isosceles triangle. The problem involves using given measurements and applying right triangle trigonometry to calculate unknown side lengths. The tutorial explains the properties of isosceles triangles, the use of trigonometric functions, and the process of calculating the perimeter, rounding the final answer to the nearest hundredth.

What is the measure of angle BAC in the given isosceles triangle?

• 60 degrees

• 75 degrees

• 55 degrees

• 45 degrees

If AD equals 3 units, what is the length of CD in the triangle?

• 5 units

• 4 units

• 3 units

• 2 units

What is the total length of side AC in the triangle?

• 9 units

• 3 units

• 6 units

• 5 units

Which side of the triangle is bisected by segment BD?

• Side AB

• Side AD

• Side AC

• Side BC

What is the role of segment BD in the triangle?

• It is a tangent

• It is an altitude

• It is a median

• It is a perpendicular bisector

Which trigonometric function is used to find the length of side AB?

• Sine

• Tangent

• Cosine

• Secant

In the trigonometric equation, what does the adjacent side refer to?

• Side CD

• Side AD

• Side AC

• Side AB

What is the approximate length of side AB after solving the trigonometric equation?

• 4.23 units

• 5.23 units

• 6.23 units

• 7.23 units

What is the perimeter of the isosceles triangle ABC?

• 17.46 units

• 16.46 units

• 15.46 units

• 14.46 units

What is the final step in calculating the perimeter of the triangle?

• Adding the lengths of AB and AC

• Adding the lengths of AB, BC, and AC

• Adding the lengths of AB and BC

• Adding the lengths of AC and BC