Class IX Math
Hots For Lines and Angles
1. In the given figure, AOC is a line, find x.
2. In the given figure,
intersect at O.
(a) Determine y, when x = 60°.
(b) Determine x, when y = 40°.
3. In the given figure, lines Ab, CD and EF intersect at O.
Find the measure of ∠AOC, ∠COF.
4. The exterior angles obtained on producing the base of a triangle both ways are 100° and 120°. Find all the angles.
5. ΔABC is right angled at A and AL ┴ BC. Prove that ∠BAL = ∠ACD.
6. If two parallel lines are intersected by a transversal, prove that the bisectors of the two pairs of interior angles enclose a rectangle.
7. The angles of a triangle are arranged in ascending order of magnitude. If the difference between two consecutive angles is 10°, find all the three angles.
8. In the given figure, POQ is a line. Ray
is another ray lying between rays
and
Prove that
9. Can a triangle have two obtuse angles? Give reason for your answer.
10. How many triangles can be drawn having its angles as 45°, 64° and 72°? Give reason for your answer.