PART: A (1 mark each) 1) Give real life examples of parallel lines 2) Define centroid 3) 3)Are the two triangles given below similar? PART:B (2 marks each) 4) What can you say about a line that cuts 2 sides of a triangle in same ratio? 5)State any two conditions for similarity 6)Are the triangles given below similar? Giv om 15cm 3 2 Bom ? som PART:C (3 marks each) 7)Divide a 10cm line into 3 equal parts.
Answers
Answer:Ans 1 Parallel line examples in real life are railroad tracks, the edges of sidewalks, marking on the streets, zebra crossing on the roads, the surface of pineapple and strawberry fruit, staircase and railings, etc.
Ans 2 In mathematics and physics, the centroid or geometric center of a plane figure is the arithmetic mean position of all the points in the figure. Informally, it is the point at which a cutout of the shape could be perfectly balanced on the tip of a pin. The same definition extends to any object in n-dimensional space.
Ans3 they have congruent corresponding angles
Part b
ANS 4 If a line divides any two sides of a triangle in the same ratio, then the line is parallel to the third side.
ANS 5 Two triangles are said to be similar if their corresponding angles are congruent and the corresponding sides are in proportion . In other words, similar triangles are the same shape, but not necessarily the same size. The triangles are congruent if, in addition to this, their corresponding sides are of equal length.
Ans 6 Similar Triangles Congruent Triangles
They are the same shape but different in size They are the same in shape and size
Part c
Step 1: Draw a line segment AB of length 10 cm using a ruler.
Step 2: Draw an acute ∠CBA on one side of line AB.
Step 3: Mark points B
1
,B
2
,B
3
on ray BC such that BB
1
=B
1
B
2
=B
2
B
3
.
Step 4: Join B
3
to A.
Step 5: Draw lines B
1
E and B
2
D parallel to B
3
A and let them intersect AB in points E and D respectively.
Step-by-step explanation: