Mathematics Part ii Solutions Solutions for Class 7 Math Chapter 2 Triangular Area are provided here with simple step-by-step explanations. These solutions for Triangular Area are extremely popular among class 7 students for Math Triangular Area Solutions come handy for quickly completing your homework and preparing for exams. All questions and answers from the Mathematics Part ii Solutions Book of class 7 Math Chapter 2 are provided here for you for free. You will also love the ad-free experience on Meritnation’s Mathematics Part ii Solutions Solutions. All Mathematics Part ii Solutions Solutions for class 7 Math are prepared by experts and are 100% accurate.

Page No 108:

Question 1:

Now can’t you find the areas of these triangles?

 

Answer:

(i) Let the given triangle be ΔABC.

We know that the area of a right-angled triangle is half the product of its perpendicular sides.

∴ Area of ΔABC =

(ii) Let the given triangle be ΔABC.

We know that the area of a right-angled triangle is half the product of its perpendicular sides.

∴ Area of ΔABC =

(iii) Let the given triangle be ΔABC.

We know that the area of a right-angled triangle is half the product of its perpendicular sides.

∴ Area of ΔABC =

(iv) Let the given triangle be ΔABC.

We know that the area of a right-angled triangle is half the product of its perpendicular sides.

∴ Area of ΔABC =



Page No 109:

Question 1:

Find the areas of these figures also:

 

Answer:

(i) The named figure is shown below.

We know that the area of a rectangle is the product of the lengths of its adjacent sides.

Area of the rectangle AECF = FC × EC = 4 cm × 3 cm = 12 cm2

We know that the area of a right-angled triangle is half the product of its perpendicular sides.

∴ Area of ΔADF =

Area of ΔCEB =

Area of the given figure = Area of ΔADF + area of rectangle AECF + area of ΔCEB

= (3 + 12 + 3) cm2

= 18 cm2

(ii) The named figure is shown below.

We know that the area of a rectangle is the product of the lengths of its adjacent sides.

Area of rectangle ABFE = EF × AE = 5 cm × 2 cm = 10 cm2

We know that the area of a right-angled triangle is half the product of its perpendicular sides.

∴ Area of ΔADE =

Area of ΔBFC =

Area of the given figure = Area of ΔADE + area of rectangle ABFE + area of ΔBFC

= (1 + 10 + 1) cm2

= 12 cm2

(iii) The named figure is shown below.

We know that the area of a right-angled triangle is half the product of its perpendicular sides.

∴ Area of ΔADB =

Area of ΔADC =

Area of the given figure = Area of ΔADB + area of ΔADC

= (3 + 3) cm2

= 6 cm2

(iv) The named figure is shown below.

We know that the area of a right-angled triangle is half the product of its perpendicular sides.

Area of ΔADB =

Area of ΔADC =

Area of the given figure = Area of ΔADB + area of ΔADC

= (4 + 6) cm2

= 10 cm2



Page No 113:

Question 1:

Now can’t you find the areas of these triangles?

 

Answer:

(i) Let the given triangle be ΔABC and AD be the altitude of ΔABC.

We know that the area of a triangle is half the product of any side and the altitude to it.

∴ Area of ΔABC =

(ii) Let the given triangle be ΔABC and CD be the altitude of ΔABC.

We know that the area of a triangle is half the product of any side and the altitude to it.

∴ Area of ΔABC =

(iii) Let the given triangle be ΔABC and AD be the altitude of ΔABC.

We know that the area of a triangle is half the product of any side and the altitude to it.

∴ Area of ΔABC =

Page No 113:

Question 2:

Compute the altitudes to the other two sides of this triangle:

Answer:

Let the given triangle be ΔABC and AD, BE, CF be the three altitudes of ΔABC.

We know that the area of a triangle is half the product of any side and the altitude to it.

∴ Area of ΔABC =

Also, area of ΔABC =

⇒ 6 cm2 = cm

⇒ BE = = 2.4 cm

Again, area of ΔABC =

⇒ 6 cm2 = cm

⇒ CF = = 3 cm

Thus, the lengths of the other altitudes are 2.4 cm and 3 cm.



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