Practice the problems of Math in Focus Grade 7 Workbook Answer Key Chapter 7 Geometric Construction to score better marks in the exam.

## Math in Focus Grade 7 Course 2 B Chapter 7 Answer Key Geometric Construction

### Math in Focus Grade 7 Chapter 7 Quick Check Answer Key

**Copy and complete the table by classifying the triangles.**

Question 1.

Answer:

Figure A is an Equilateral Triangle.

Figure B is an Isosceles Triangle.

Figure E is a Right Triangle.

Figure F is an Acute angle Triangle.

Figure C is an Obtuse angle Triangle

Explanation:

1. Equilateral triangle: In an equilateral triangle each angle is 60°. All sides and lengths of an equilateral triangle are equal. From the given figure we can classify that figure A is an Equilateral triangle.

2. Isosceles triangle: In the isosceles triangle only two sides are equal, the number of vertices and the number of edges are 3. By observing the given diagram figure B is called an Isosceles triangle

3. Right Triangle: A right-angled triangle is a triangle in which one of the angles is 90 degrees. Figure E is called a right-angled triangle.

4. Acute triangle: An acute angle is an angle that is less than 90. Since all the three angles are less than 90° then it is called an acute angle. Figure F is an acute angle from the above diagram.

5. Obtuse triangle: Obtuse angle is an angle that has greater than 90°. The figure C is called an obtuse triangle.

**Copy and complete the table.**

Question 2.

Answer:

1. Square: All sides are equal.

2. Rectangle: Rectangle is a quadrilateral with four right angles. The area of a rectangle is length width.

3.Trapezium: Trapezium has four vertices and four sides.

4. Parallelogram: In a parallelogram, both sides are parallel and equal.

5. Square parallelogram: The diagonals have equal length.

Explanation:

**Measure ∠ABC.**

Question 3.

Answer:

∠ABC has 60° which is an acute angle triangle.

Explanation:

An acute angle is an angle that has less than 90°. The figure given here has less than 90° and the measure of that angle is 60°.

Question 4.

Answer:

The measurement of ∠ABC is 80°. And it is an acute angle triangle.

Explanation:

An acute angle is an angle that has less than 90°. The figure given here has less than 90° and the measure of that angle is 80°.

Question 5.

Answer:

The measurement of ∠ABC is 110°.

Explanation:

An obtuse angle is an angle that has greater than 90°. From the given figure we can measure the angle ∠ABC has 110°

Question 6.

Answer:

The measurement of ∠ABC is 120°which is an obtuse angle triangle.

Explanation:

An obtuse angle is an angle that has greater than 90°. From the given figure we can measure the angle ∠ABC has 120°

**Use a protractor to draw each angle.**

Question 7.

m∠DEF = 39°

Answer:

Angle DEF is an acute angle and the angle between 90° to 180°.

Explanation:

Question 8.

m∠XYZ = 92°

Answer:

Angle XYZ has a right angle and it is 92°.

Explanation:

Question 9.

m∠PQR = 146°

Answer:

Angle PQR is 146°.

Explanation:

Copy \(\overleftrightarrow{\mathbf{A B}}\), \(\overleftrightarrow{\mathbf{C D}}\), and \(\overleftrightarrow{\mathbf{X Y}}\) on a sheet of paper. Draw a perpendicular line to each given line.

Question 10.

Answer:

We take the straight line AB They insect at each at a right angle.

Explanation:

Question 11.

Answer:

We take a straight line CD, then draw a perpendicular line XY between the line CD. They insect each at a right angle.

Explanation:

Question 12.

Answer:

We take the straight line XY, then draw a perpendicular line AB between the line XY. The angle insects are at a right angle.

Explanation: