Practice the problems of Math in Focus Grade 4 Workbook Answer Key Chapter 9 Practice 1 Understanding and Measuring Angles to score better marks in the exam.
Math in Focus Grade 4 Chapter 9 Practice 1 Answer Key Understanding and Measuring Angles
Name the angles in two ways.
Example
Question 1.
Answer:
∠STU or ∠UTS.
Explanation:
The name of the angle T is ∠STU or ∠UTS.
Question 2.
Answer:
∠XYZ or ∠ZYX.
Explanation:
The name of the angle Y is ∠XYZ or ∠ZYX.
Question 3.
Angle at A: ∠___ or ∠___
Angle at B: ∠___ or ∠___
Angle at C: ∠___ or ∠___
Answer:
∠BAC or ∠CAB,
∠ABC or ∠CBA,
∠BCA or ∠ACB.
Explanation:
The name of angle A is ∠BAC or ∠CAB.
The name of angle B is ∠ABC or ∠CBA.
The name of angle A is ∠BCA or ∠ACB.
Name the marked angles in two ways.
Example
∠p: ∠AED or ∠DEA
Question 4.
∠q: ∠____ or ∠_____
Answer:
∠q: ∠EDC or ∠CDE
Explanation:
The marked angle ∠q is ∠EDC or ∠CDE.
Question 5.
∠r: ∠____ or ∠_____
Answer:
∠r: ∠BCD or ∠DCB.
Explanation:
The marked angle ∠r is ∠BCD or ∠DCB.
Question 6.
∠s: ∠____ or ∠_____
Answer:
∠s: ∠BAE or ∠EAB.
Explanation:
The marked angle ∠s is ∠BAE or ∠EAB.
Name the marked angles in two ways.
Question 7.
∠PRQ: ∠___ or ∠___
Answer:
∠PRQ: ∠b or ∠QRP.
Explanation:
The name of the marked ∠PRQ is ∠b or ∠QRP.
Question 8.
∠QPR: ∠___ or ∠___
Answer:
∠QPR: ∠a or ∠RPQ.
Explanation:
The name of the marked ∠QPR is ∠a or ∠RPQ.
Decide which scale you would use to measure each angle.
Fill in the blanks with inner scale or outer scale.
Examples
Question 9.
Answer:
Outer scale.
Explanation:
Here, the angle opens to the left of the protractor, so the shown image is an outer scale.
Question 10.
Answer:
Outer scale.
Explanation:
Here, the angle opens to the left of the protractor, so the shown image is an outer scale.
Question 11.
Answer:
Inner scale.
Explanation:
Here, the angle opens to the right of the protractor, so the shown image is an inner scale.
Question 12.
Answer:
Inner scale.
Explanation:
Here, the angle opens to the left of the protractor, so the shown image is an inner scale.
Peter is walking along a path. Measure the marked angles along this path.
Question 17.
Answer:
Explanation:
Here, the measure of ∠FGH = 80°,
the measure of ∠EFG = 75°,
the measure of ∠CDE = 80°,
the measure of ∠GHI = 20°,
the measure of ∠DEF = 70°