Match the angles with their correct measurement. A A B B (a) 270 ° (i) (b) 90 ° (ii) (c) 145 ° (iii) (d) 180 ° (iv) (e) 45 ° (v) (f) 75 ° (vi)

Given to match the angles with correct measurement. (a) 270 ° We know that, The highest measurement in angle is 270 ° . Thus, by measuring all the figures, the above figure is 270 ° . (b) 90 ° We know that, The angle of right angle is 90 ° . Thus, the above figure is 90 ° . (c) 145 ° We know that, The angle more than the 90 ° is Obtuse angle. Thus, the above figure has more than the 90 ° and the angle measured is 145 ° . (d) 180 ° The angle of straight angle is 180 ° . Thus, the above figure is straight angle having 180 ° . (e) 45 ° The angle less than 90 ° is acute angle. The above figure is acute angle having 45 ° . (f) 75 ° The angle less than 90 ° is acute angle. Thus, the above figure is acute angle having 75 ° . Therefore, the correct answers shown in below table. A A B B (a) 270 ° (i) (b) 90 ° (ii) (c) 145 ° (iii) (d) 180 ° (iv) (e) 45 ° (v) (f) 75 ° (vi)

Construct angle 30 ∘ using protractor and a ruler.

Given, to draw an angle 30 ∘ using protractor and ruler. Construct an angle B O A equal to 30 ° . Draw a ray O A using a ruler. Place the centre of the protractor at O of the ray O A . Adjust the protractor so that the baseline of the protractor is on the ray O . Now the ray is a straight line measuring 30 ∘ . Mark a point at 30 ° and name it as B. Join point B with O. Hence, ∠ B O A = 30 ∘ is the required angle.

Construct angle 90 ∘ using protractor and a ruler.

Given, To draw an angle 90 ∘ using protractor and ruler. Construct an angle B O A equal to 90 ° , Draw a ray O A using a ruler. Place the centre of the protractor at O of the ray O A . Adjust the protractor so that the baseline of the protractor is on the ray O . Now the ray is a straight line measuring 90 ∘ , Mark a point at 90 ° and name it as B. Join point B with O. Hence ∠ B O A = 90 ∘ is the required angle.

Construct angle 135 ∘ using protractor and a ruler.

Given, To draw an angle 135 ∘ using protractor and ruler. Construct an angle B O A equal to 135 ° , Draw a ray O A using a ruler. Place the centre of the protractor at O of the ray O A . Adjust the protractor so that the baseline of the protractor is on the ray O . Now the ray is a straight line measuring 135 ∘ , Mark a point at 135 ° and name it as B. Join point B with O. Hence ∠ B O A = 1 3 5 ∘ is the required angle.

Construct angle 270 ∘ using protractor and a ruler.

Draw a ray AB using a ruler. Put the point of the compass at A and draw an arc that cuts the line AB and mark that cut point as C. Put the point of the compass at C and draw an arc of radius AC that cuts the arc drawn in Step 2 and mark the intersection point as D. Keeping the compass at D, draw an arc of radius AC using a compass to cut the arc drawn in Step 2 and mark the intersection point as E. Keeping the compass at point D, draw another arc using the same radius AC between points D and E. Now keeping the compass at point E, draw another arc using the same radius AC to cut the arc drawn in step 5 and mark the intersection point as F. Join F and A. The angle FAB is a 90 - degree angle. The reflex angle FAB will be equal to the full angle-angle FAB, i.e., reflex angle FAB = 360 ° - 90 ° = 270 ° . Thus, reflex angle FAB is the required angle of 270 0 .