Kerala Syllabus Class 7 Mathematics - Unit 10 Area of Triangles - Questions and Answers | Teaching Manual 

Questions and Answers for Class 7 Mathematics - Unit 10 Area of Triangles - Study Notes | Text Books Solution STD 7 - Maths: Unit 10 Area of Triangles - Questions and Answers | ഗണിതം - ത്രികോണപ്പരപ്പ് - ചോദ്യോത്തരങ്ങൾ 

ഏഴാം ക്ലാസ്സ്‌  Mathematics - Unit 10 Area of Triangles എന്ന പാഠം ആസ്പദമാക്കി തയ്യാറാക്കിയ ചോദ്യോത്തരങ്ങള്‍. ഈ അധ്യായത്തിന്റെ Teachers Handbook, Teaching Manual എന്നിവ ഡൗൺലോഡ് ചെയ്യാനുള്ള ലിങ്ക് ചോദ്യോത്തരങ്ങളുടെ അവസാനം നൽകിയിട്ടുണ്ട്. പുതിയ അപ്‌ഡേറ്റുകൾക്കായി ഞങ്ങളുടെ Telegram Channel ൽ ജോയിൻ ചെയ്യുക.

Kerala Syllabus STD 7 Maths: Unit 10 Area of Triangles - Textbook Solutions

♦ Textbook Activities (Textbook Page No: 138)
The area of a right triangle is half the product of its perpendicular sides.
♦ Now try these problems:
♦ Calculate the area of the triangles shown below?

Answer:
If we add these areas, we get the area of the given triangle.
∴ Area of the given triangle = ⁹⁄₂ + ⁹⁄₂ = ¹⁸⁄₂ = 9 sq.cm
The area of any triangle is half the product of one of the sides and the height from this side to the opposite vertex
The area of any triangle is half the product of the base and the altitude
♦ Textbook Activities (Textbook Page No: 142)
♦ Now try these problems:
(1) Find the areas of the triangles shown below:
Answer:
(2) What is the area of the triangle shown below?
Answer:

(i) Draw a right triangle of the same area
(ii) Draw a triangle of the same area with one angle greater than a right angle
Here, the base is 7 cm and one of the angles is 105°.
Since the height of the triangle is 4 cm. The area doesn't change.

♦ Textbook Activities (Textbook Page No: 146)
All triangles with the same base and third vertex on a line parallel to the base, have the same area
♦ Now try these problems:
(1) Draw a triangle of sides 3, 4 and 6 centimetres. Draw three different right triangles of the same area.
Answer:
(2)  How many different triangles can be drawn with two sides 8 centimetres, 6 centimetres and area 12 square centimetres? What if the area is to be 24 square centimetres?
Answer: We can draw two triangles with two sides 8 cm, 6 cm and area 12 sq.cm.
We can draw two triangles with base 8 cm and height 3 cm. In both of these triangles, area = 12 sq.cm.
But only one triangle can be drawn with two sides equal to 8 cm and 6 cm, having an area of 24 sq cm.

(3)  Draw the triangle below in the notebook:
Draw triangles ABP, BCQ and CAR of the same area with angles as given below:
(i) ∠BAP = 90°  
(ii)  ∠CBQ = 60°
(iii)   ∠ACR = 30°
Answer:
♦ Samagra Questions and Answers:
(1) What is the area of this triangle?
Answer: 9

(2) Find the area of this triangle?
Answer: 6