Chapter 11, Problem 10STP

To determine

To calculate the area of the composite figure.

Answer to Problem 10STP

  $91$ square centimeters.

Explanation of Solution

Given information:

The figure consists of a rectangle and a triangle.

Rectangle has a length of $l=10.9$ centimeters and breadth $b=7.4$ centimeters.

Triangle has a base $B=10.9-6.5$

  $=4.4$ centimeters and height $H=12.1-7.4$

  $=4.7$ centimeters.

Formula used: Area of rectangle $a=l\times b$ where ‘l’ is the length and ‘b’ is the breadth.

Area of triangle $t=\frac{1}{2}\times B\times H$ where ‘B’ is the base and ‘H’ is the height.

Calculation:

Area of the rectangle

  $a=l\times b$

Putting values in the same

  $=10.9\times 7.4$

Multiply the expression

  $=80.66$ square centimeters

Area of triangle.

  $t=\frac{1}{2}\times B\times H$

Formula for area of triangle.

  $=\frac{1}{2}\times 4.4\times 4.7$

Putting the values in the formula

  $=2.2\times 4.7$

Dividing common terms and simplifying

  $=10.34$ square centimeters.

Now, add the two areas to get the area of the given figure.

  $=a+t$

  $=80.66+10.34$

On adding the two areas, the area of the composite figure is found.

  $=91$ square centimeters,