Class 7 triangles worksheet

A worksheet on Triangle properties

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St. Joseph’s International School, Hisar
Class: VII Name:____________________ Roll No. ___
Subject: Mathematics Chapter: Triangle and its properties
1. Fill in the banks:
(i) Triangle is formed by joining three ______________ points.
(ii) A point where two sides of a triangle meet is known as ______________ of a triangle.
(iii) Each angle of an equilateral triangle is of ______________ measure.
(iv) A ______________ triangle has one angle of 90°.
(v) A triangle has ______________ vertices and ______________ sides.
(vi) In an obtuse triangle, the remaining two angles are ______________
(vii) The sum of the measure of three angles of a triangle is ______________
(viii) A triangle whose two sides are of equal length is known as ______________ triangle.
2. ABCD is a quadrilateral. Show that: AB + BC + CD + DA > AC + BD .
3. (i) A ladder is placed along a wall at a distance of 5 m from it. The ladder touches a window in the wall at a height of
12 m. Find the length of the ladder.

(ii) A ladder of length 13m is placed along a wall at a height of 12m. Find the distance of foot of ladder from wall.
4. In the above figure, P is a point on the side BC of ∆ ABC. Prove that
AB + BC + AC > 2AP

5. In the above figure, the school and library roads meet at an angle of 90°, find the distance between Nelson Middle
School and Library.
6. Refer to ∆ABC and name the following.
(i) a median of ∆ABC ________

2. (ii) an altitude of ∆ABC________
(iii) a bisector of an angle of ∆ABC ___________
7. In a triangle, if the second angle is 5° greater than the first angle and the third angle is 5° greater than second angle,
find the three angles of the triangle.
8. In a triangle, if the second angle is 2 times the first angle and the third angle is 3 times the first angle, find the angles
of the triangle.
9. If the angles of a triangle are in the ratio 2 : 7 : 11, then find the angles.
10. If 3 consecutive positive integers be the angles of a triangle, then find the three angles of the triangle.
11. In a triangle, if the second angle is 2 times the first angle and the third angle is 3 times the first angle, find the angles
of the triangle.
12. Find the value of unknowns.