Question

How many degrees are there in …………………………………
$\left( i \right)$ One right angle
$\left( {ii} \right)$ Two right angles
$\left( {iii} \right)$ Three right angle
$\left( {iv} \right)$ Four right angles
$\left( v \right)$ $\dfrac{2}{3}$ Right angles
$\left( {vi} \right)$ $1\dfrac{1}{2}$ Right angles

Answer 1

Hint: In this question use the concept that one right angle corresponds to ${90^0}$, thus use a unitary method to calculate the corresponding degree values for the asked number of right angles.

Complete step-by-step answer:

As we know the right angle is an angle which is at $90^0$ as shown in figure.
So,
$\left( i \right)$ One right angle = ${90^0}$
$\left( {ii} \right)$ Two right angles = $2 \times {90^0} = {180^0}$
$\left( {iii} \right)$ Three right angle = $3 \times {90^0} = {270^0}$
$\left( {iv} \right)$ Four right angles = $4 \times {90^0} = {360^0}$
$\left( v \right)$ $\dfrac{2}{3}$ right angles = $\dfrac{2}{3} \times {90^0} = {60^0}$
$\left( {vi} \right)$ $1\dfrac{1}{2}$ right angle
Convert this fraction into improper fraction so we have,
$ \Rightarrow 1\dfrac{1}{2} = \dfrac{{1 \times 2 + 1}}{2} = \dfrac{3}{2}$
Therefore $\dfrac{3}{2}$ right angles = $\dfrac{3}{2} \times {90^0} = {135^0}$
So this is the required answer.

Note – Here we came across a mixed fraction in the last option. Mixed fraction is one in which a whole number and a fraction is combined into one. Conversion of this mixed fraction into improper fraction was necessary in order for the application of the unitary method. An improper fraction is one in which the numerator is greater than the denominator.