3. Draw a picture that shows the trapezoidal stone and the information that you know: (1 point) 4. Is this is an isosceles trapezoid? How do you know? (1 point)
7. U:
Understand the problem: Measuring an existing arch.
Part 1: Serena's drawing
Follow these steps to find the angles of the trapezoids in Serena's drawing. If the angles of her
trapezoid match the angles of the trapezoid stone, then her drawing is correct.
8. Find
D
E
R
B!
с
BAC=20
DB caluo
BOE=80
Sa
5. Find the measure of angle BAC. Hint: What is the sum of the measures of the vertex angles of the
nine congruent isosceles triangles? (1 point)
BAC 20
U