Envision Math 5th Grade Textbook Answer Key Topic 20 Reteaching
Reteaching
Set A, pages 452-453
Construct an angle congruent to angle A.
Answer:
Draw a ray with endpoint E.
With point A as center, use your compass to draw an arc that intersects both sides of angle A. Label the points of intersection R and S. With the same compass setting, use point E as center and draw an arc that intersects the ray at point D.
Open the compass to length RS. Then, with point D as center, draw an intersecting arc.
Label the intersection F. Use a straightedge to draw ray EF.
Angle E is congruent to angle A.
Remember that a construction uses only a compass and a straightedge.
Construct an angle congruent to the given angle.
Question 1.
Answer:
Question 2.
Answer:
Set B, pages 454-456
Construct a line perpendicular to another line.
Answer:
- Draw line AB.
- With A as center, draw two arcs that intersect line AB. Label the points of intersection D and E.
- Open the compass wider.
- Using D and E as centers, draw arcs that intersect. Label the intersection C.
- Draw Line CA.
- Line CA is perpendicular to line AB.
Remember to keep the compass open to the same setting when drawing the arcs with D and E as the centers.
Question 1.
Construct a line perpendicular to another line.
Answer:
Question 2.
For the construction started below, what is the next step to construct a line perpendicular to line XY?
Answer:
Set C, pages 458-460
Construct a triangle congruent to triangle DEF.
Answer:
- Draw a ray with endpoint G.
- Construct angle G.
- Congruent to angle D.
- Construct segments GK and GL on the sides of angle G so that they are congruent to segments DE and DF.
- Draw segment KL.
- Triangle GKL is congruent to triangle DEF.
Construct a rectangle ABCD.
Answer:
- Draw line AB.
- Construct line DA perpendicular to line AB at A.
- Construct line DC perpendicular to line DA at D.
- Construct line CB perpendicular to line AB at B.
- Lines DC and CB intersect at C.
Remember to use the compass to measure the length of the original line segments by placing the point on one endpoint and the slider on the other endpoint.
Question 1.
Construct a triangle congruent to triangle XYZ.
Answer:
Question 2.
Construct a rectangle KLMN.
Answer:
Set D, pages 462-463
When you use objects to solve problems, follow these steps.
Step 1: Choose objects that can best model what is described in the problem.
Step 2: Use the objects to make a model of what you know.
Step 3: Use the objects to act out the action in the problem. Look for patterns.
Step 4: Find the answer in your model.
Remember to state clearly at the beginning what your objects represent in the problem.
Question 1.
How many total bricks are needed if the pattern extends to 4 bricks in the middle row?
Answer: